Currently sub-property binding is supported in the MasterTemplate of the grid (level 1). We should make this functionality available in lower levels when users are creating an object relational hierarchy.

Steps to reproduce:
1. Use the RadGridView Smart Tag to set its data source 
2. Press "Add Project DataSource"
3. Select "Object"
4. Drill down and select the class you created. (see below)
5. Select the New Data Source
6. Run the project 

Code to reproduce:

public class TestClass
{
public enum Month { January, Febuary, March, April, May, June, July, August, September, October, November, December }
public Month TestMonth {get; set;}
public String TestMessage {get; set;}
public TestClass(Month month, String message)
{
TestMonth = month; TestMessage = message; }
}

Workaround:
Use BindingList instead System.Windows.Forms.BindingSource.

Add support for the GridViewComboBoxColumn to initialize properly when the BindingList it is bound to is empty.

After a couple clicks, grid's context menu becomes unresponsive when using RadGridView through remote connection and Windows 7

Customize the default DateTime filtering in order to allow scenarios, when the end users enters both date and time part, or only time and filter is applied based on the chosen criteria.

Currently, if there are not enough rows to fill the height of RadGridView control, the pinned row will appear right after the last row. It will be good to facilitate customization that sets the pinned row to appear at the bottom of the grid. Same logic holds for summary rows and columns.

Workaround:

public Form1()
{
    InitializeComponent();

    DataTable dt = new DataTable();
    dt.Columns.Add("Id");
    dt.Columns.Add("Name");
    for (int i = 0; i < 5; i++)
    {
        dt.Rows.Add(i, "Item" + i);
    }

    this.radGridView1.DataSource = dt;
    this.radGridView1.AutoSizeColumnsMode = Telerik.WinControls.UI.GridViewAutoSizeColumnsMode.Fill;

    this.radGridView1.AllowSearchRow = true;
    this.radGridView1.SearchRowPosition = Telerik.WinControls.UI.SystemRowPosition.Bottom;

    this.radGridView1.ViewDefinition = new CustomTableViewDefition();
}

public class CustomTableViewDefition : TableViewDefinition
{
    public override IRowView CreateViewUIElement(GridViewInfo viewInfo)
    {
        return new CustomTableElement();
    }
}

public class CustomTableElement : GridTableElement
{
    protected override RowsContainerElement CreateViewElement()
    {
        return new CustomRowsContainerElement();
    }
}

public class CustomRowsContainerElement : RowsContainerElement
{
    protected override SizeF ArrangeOverride(SizeF finalSize)
    {
        float y = 0;

        this.TopPinnedRows.Arrange(new RectangleF(0, y, finalSize.Width, this.TopPinnedRows.DesiredSize.Height));
        y += this.TopPinnedRows.DesiredSize.Height + ElementSpacing;

        this.ScrollableRows.Arrange(new RectangleF(0, y, finalSize.Width, this.ScrollableRows.DesiredSize.Height));
        y += this.ScrollableRows.DesiredSize.Height + ElementSpacing;

        this.BottomPinnedRows.Arrange(new RectangleF(0, finalSize.Height - this.BottomPinnedRows.DesiredSize.Height,
            finalSize.Width, this.BottomPinnedRows.DesiredSize.Height));

        return finalSize;
    }
}

The GroupRow Height cannot be changed when ColumnGroupsViewDefinition and HtmlViewDefinition are used.

1. Create a new project with RadGridView and set MultiSelect to true and SelectionMode to CellSelect.
2. Run the project.
3. Use the mouse to select some cells and scroll down while selecting.
4. Remove some cells from the selection.
5. Scroll with the scrollbar up to the first selected cells. You will see that all previously selected cells which are not visible are not selected.

Workaround:
Use the following custom behavior:
public class MyGridRowBehavior : GridDataRowBehavior
{
    private FieldInfo oldCurrentLocationFieldInfo;
    private Point oldCurrentLocation
    {
        get
        {
            if (this.oldCurrentLocationFieldInfo == null)
            {
                this.oldCurrentLocationFieldInfo = typeof(GridRowBehavior).GetField("oldCurrentLocation", BindingFlags.Instance | BindingFlags.NonPublic);
            }

            return (Point)this.oldCurrentLocationFieldInfo.GetValue(this);
        }
        set
        {
            this.oldCurrentLocationFieldInfo.SetValue(this, value);
        }
    }

    private MethodInfo selectIntersectedCellsMethodInfo;
    private delegate void SelectIntersectedCellsDelegate(RadElementCollection rows, bool isProcessedShiftOrControl);
    private SelectIntersectedCellsDelegate SelectIntersectedCellsCore;
    private void SelectIntersectedCells(RadElementCollection rows, bool isProcessedShiftOrControl)
    {
        if (this.selectIntersectedCellsMethodInfo == null)
        {
            this.selectIntersectedCellsMethodInfo = typeof(GridRowBehavior).GetMethods(BindingFlags.Instance | BindingFlags.NonPublic).First(x => x.Name == "SelectIntersectedCells" && x.GetParameters().Length == 2);
            this.SelectIntersectedCellsCore = (SelectIntersectedCellsDelegate)Delegate.CreateDelegate(typeof(SelectIntersectedCellsDelegate), this, this.selectIntersectedCellsMethodInfo);
        }

        this.SelectIntersectedCellsCore(rows, isProcessedShiftOrControl);
    }

    private MethodInfo selectIntersectedRowsMethodInfo;
    private delegate bool SelectIntersectedRowsDelegate(RadElementCollection rows);
    private SelectIntersectedRowsDelegate SelectIntersectedRowsCore;
    private bool SelectIntersectedRows(RadElementCollection rows)
    {
        if (this.selectIntersectedRowsMethodInfo == null)
        {
            this.selectIntersectedRowsMethodInfo = typeof(GridRowBehavior).GetMethod("SelectIntersectedRows", BindingFlags.Instance | BindingFlags.NonPublic);
            this.SelectIntersectedRowsCore = (SelectIntersectedRowsDelegate)Delegate.CreateDelegate(typeof(SelectIntersectedRowsDelegate), this, this.selectIntersectedRowsMethodInfo);
        }

        return this.SelectIntersectedRowsCore(rows);
    }

    protected override bool ProcessMouseSelection(Point mousePosition, GridCellElement currentCell)
    {
        if (this.RootGridBehavior.LockedBehavior != this)
        {
            this.GridControl.Capture = true;
            this.RootGridBehavior.LockBehavior(this);
        }

        GridCellElement mouseDownCell = this.GetCellAtPoint(this.MouseDownLocation);
        GridCellElement oldCurrentCell = this.GetCellAtPoint(this.oldCurrentLocation);

        bool isValidResizingContext = this.ResizeSelectionRectangle(currentCell, mousePosition);
        bool result = false;

        if (isValidResizingContext && oldCurrentCell != currentCell)
        {
            if (this.MasterTemplate.MultiSelect && !this.GridViewElement.Template.AllowRowReorder)
            {
                if (this.MasterTemplate.SelectionMode == GridViewSelectionMode.FullRowSelect)
                {
                    bool selectedRowsChanged = false;
                    bool isPressedShiftOrControl = (this.IsPressedShift || this.IsPressedControl);

                    GridTableElement tableElement = this.GridViewElement.CurrentView as GridTableElement;
                    RadElementCollection scrollableRows = tableElement.ViewElement.ScrollableRows.Children;
                    RadElementCollection topPinnedRows = tableElement.ViewElement.TopPinnedRows.Children;
                    RadElementCollection bottomPinnedRows = tableElement.ViewElement.BottomPinnedRows.Children;
                    GridViewRowInfo[] selectedRows = this.MasterTemplate.SelectedRows.ToArray();

                    tableElement.BeginUpdate();

                    int oldSelectedRows = this.MasterTemplate.SelectedRows.Count;

                    if (!isPressedShiftOrControl)
                    {
                        for (int i = selectedRows.Length - 1; i >= 0; i--)
                        {
                            GridViewRowInfo rowInfo = selectedRows[i];
                            GridRowElement rowElement = tableElement.GetRowElement(rowInfo);

                            bool select = rowElement != null &&
                                                 rowElement.ControlBoundingRectangle.IntersectsWith(this.GridViewElement.SelectionRectangle);

                            if (select)
                            {
                                rowInfo.IsSelected = true;
                            }

                            if (!rowInfo.IsSelected)
                            {
                                selectedRowsChanged = true;
                            }
                        }
                    }

                    selectedRowsChanged = this.SelectIntersectedRows(topPinnedRows);
                    selectedRowsChanged |= this.SelectIntersectedRows(scrollableRows);
                    selectedRowsChanged |= this.SelectIntersectedRows(bottomPinnedRows);

                    if (oldSelectedRows != this.MasterTemplate.SelectedRows.Count)
                    {
                        selectedRowsChanged = true;
                    }

                    tableElement.EndUpdate(false);
                }
                else
                {
                    GridTableElement tableElement = this.GridViewElement.CurrentView as GridTableElement;

                    if (tableElement == null)
                    {
                        return result;
                    }

                    CancelEventArgs cancelArgs = new CancelEventArgs();
                    this.MasterTemplate.EventDispatcher.RaiseEvent<CancelEventArgs>(EventDispatcher.SelectionChanging, this, cancelArgs);
                    if (cancelArgs.Cancel)
                    {
                        return result;
                    }
                    
                    //Since version Q2 2014 (version 2014.2.617), please use:
                    //GridViewSelectionCancelEventArgs cancelArgs = new GridViewSelectionCancelEventArgs(this.MasterTemplate.CurrentRow, this.MasterTemplate.CurrentColumn);
                    //this.MasterTemplate.EventDispatcher.RaiseEvent<GridViewSelectionCancelEventArgs>(EventDispatcher.SelectionChanging, this, cancelArgs);
                    //if (cancelArgs.Cancel)
                    //{
                    //    return result;
                    //}

                    this.GridViewElement.CurrentView.BeginUpdate();
                    bool isProcessedShiftOrControl = (this.IsPressedShift || this.IsPressedControl);

                    int count = this.MasterTemplate.SelectedCells.Count;
                    RadElementCollection scrollableRows = tableElement.ViewElement.ScrollableRows.Children;
                    RadElementCollection topPinnedRows = tableElement.ViewElement.TopPinnedRows.Children;
                    RadElementCollection bottomPinnedRows = tableElement.ViewElement.BottomPinnedRows.Children;

                    this.SelectIntersectedCells(scrollableRows, isProcessedShiftOrControl);
                    this.SelectIntersectedCells(topPinnedRows, isProcessedShiftOrControl);
                    this.SelectIntersectedCells(bottomPinnedRows, isProcessedShiftOrControl);

                    bool notifyUpdates = true;

                    if (isProcessedShiftOrControl)
                    {
                        notifyUpdates = count != this.MasterTemplate.SelectedCells.Count;
                    }

                    this.GridViewElement.CurrentView.EndUpdate(false);

                    this.GridViewElement.Invalidate();
                }

                result = true;
            }

            result = false;
        }

        this.oldCurrentLocation = mousePosition;
        return result;
    }
}


Register the new behavior as follows:

BaseGridBehavior behavior = (BaseGridBehavior)this.radGridView1.GridBehavior;
behavior.UnregisterBehavior(typeof(GridViewDataRowInfo));
behavior.RegisterBehavior(typeof(GridViewDataRowInfo), new MyGridRowBehavior());

Consider the iTunes Artist mode grid
http://www.telerik.com/forums/itunes-like-grid

Presently it is not possible to persist customer created formatting objects in RadGridView.

debug attached sample application

steps:

set number of rows to 500
change to 2nd page
change to 1st page
set number of rows to 0
change to 2nd page

FIX. RadGridView - the PropertyName from the arguments of the RowsChanged event is null, while it should display the changed field name

To reproduce, use the following localization provider and set a fitler to a boolean column in RadGridView, via the Custom filtering dialog.

  class MyRadGridLocalizationProvider : RadGridLocalizationProvider
        {
            public const string CustomTrue = "CustomTRUE";
            public const string CustomFalse = "CustomFALSE";

            public override string GetLocalizedString(string id)
            {
                if (id == "CustomFilterDialogTrue")
                {
                    return CustomTrue;
                }
                else if (id == "CustomFilterDialogFalse")
                {
                    return CustomFalse;
                }
                else
                {
                    return base.GetLocalizedString(id);
                }
            }
        }

Workaround - create custom type converter as follows:
        public class MyBooleanConverter : BooleanConverter
        {
            public override object ConvertFrom(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value)
            {
                if (value is string)
                {
                    string text = Convert.ToString(value);

                    if (text == MyRadGridLocalizationProvider.CustomTrue)
                    {
                        return true;
                    }
                    else if (text == MyRadGridLocalizationProvider.CustomFalse)
                    {
                        return false;
                    }
                }
                return base.ConvertFrom(context, culture, value);
            }
        }

and apply it to the check box column:
   radGridView1.Columns["BoolColumn"].DataTypeConverter = new MyBooleanConverter();

To reproduce set AddNewRowPosition is Bottom and the NewRowEnterKeyMode is EnterMovesToNextCell and add a new row via na UI

Workaround:
        void radGridView1_RowsChanged(object sender, GridViewCollectionChangedEventArgs e)
        {
            if (e.Action == NotifyCollectionChangedAction.Add && radGridView1.CurrentRow is GridViewNewRowInfo)
            {

            }
        }

The column image setting overrides the local image setting. 

Work around:
void grid_CellFormatting(object sender, CellFormattingEventArgs e)
       {
           if (e.CellElement is GridCommandCellElement)
           {
               if (e.Column.Name == "stationview")
               {
                   RadButtonElement element = (RadButtonElement)e.CellElement.Children[0];
                   element.UnbindProperty(RadButtonElement.ImageProperty);
                   element.Image = img;
                   element.DisplayStyle = DisplayStyle.Image;
                   element.ImageAlignment = ContentAlignment.MiddleCenter;
               }
           }
       }

To reproduce:
void radGridView1_CurrentRowChanged(object sender, Telerik.WinControls.UI.CurrentRowChangedEventArgs e)
        {
            e.CurrentRow.Cells[2].ColumnInfo.IsCurrent = true;
        }

ADD. RadGridView - add functionality to automatically scroll to the needed position, during multiple selection of cells with the traslucent rectangle.
MultiSelect = true
SelectionMode = cells

ADD. RadGridView - add the ability to group by a certain column and display the groups sorted by the values of another column

To reproduce:
Add a RadGridView and use the following code. When you expand the first row, the vertical scrollbar is not correct. Scrolling down changes its size. However, if you expand the last row, it takes few seconds to open.

Second scenario:
In addition of the following code, if you change the TableElement.PageViewMode to PageViewMode.ExplorerBar, expanding the first row takes few seconds to load the hierarchical data as well.

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        List<Item> items = new List<Item>();
        List<SubItem> subItems = new List<SubItem>();

        for (int i = 1; i <= 3; i++)
        {
            Item item = new Item(i, "Item" + i);
            
            for (int j = 1000; j <= 2010; j++)
            {
                subItems.Add(new SubItem(j, "SubItem" + j, i));
            }

            items.Add(item);
        }

        this.radGridView1.DataSource = items;
        this.radGridView1.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;

        GridViewTemplate template = new GridViewTemplate();
        template.ReadOnly = true;
        template.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;

        GridViewRelation relation = new GridViewRelation(this.radGridView1.MasterTemplate, template);
        relation.ParentColumnNames.Add("Id");
        relation.ChildColumnNames.Add("ItemId");
        this.radGridView1.MasterTemplate.Templates.Add(template);
        this.radGridView1.Relations.Add(relation);
        template.DataSource = subItems;
    }
}

public class Item
{
    public int Id { get; set; }

    public string Title { get; set; }

    public Item(int id, string title)
    {
        this.Id = id;
        this.Title = title;
    }
}

public class SubItem
{
    public int Id { get; set; }

    public int ItemId { get; set; }

    public string Name { get; set; }
    
    public SubItem(int id, string name, int itemId)
    {
        this.Id = id;
        this.ItemId = itemId;
        this.Name = name;
    }
}

To reproduce:

1. Add a RadGridView with two GridViewMultiComboBoxColumns at design time.
2. Bind both of the columns at design time to two different data sources.
3. In the CellEditorInitialized event, set the RadMultiColumnComboBoxElement.AutoSizeDropDownToBestFit property to true.
4. Run the application and open the editor for one of the GridViewMultiComboBoxColumns . You will notice that the columns are automatically sized to fit the content. However, if you open the editor for the other GridViewMultiComboBoxColumn, you will see that columns are not auto sized correctly.  Please refer to the attached gif file.

Workaround:
private void radGridView1_CellEditorInitialized(object sender, Telerik.WinControls.UI.GridViewCellEventArgs e)
{
    RadMultiColumnComboBoxElement mccbEditor = e.ActiveEditor as RadMultiColumnComboBoxElement;
    if (mccbEditor != null)
    {
        mccbEditor.AutoSizeDropDownToBestFit = true;
        mccbEditor.PopupOpening -= mccbEditor_PopupOpening;
        mccbEditor.PopupOpening += mccbEditor_PopupOpening;
    }
}

private void mccbEditor_PopupOpening(object sender, CancelEventArgs e)
{
    RadMultiColumnComboBoxElement mccbEditor = sender as RadMultiColumnComboBoxElement;
    if (mccbEditor != null)
    { 
        mccbEditor.EditorControl.BestFitColumns(BestFitColumnMode.AllCells);
        int width = 0;
        foreach (GridViewColumn c in mccbEditor.EditorControl.Columns)
        {
            width += c.Width;
        }
        width += mccbEditor.EditorControl.TableElement.VScrollBar.Size.Width;
        
        mccbEditor.MultiColumnPopupForm.Size = new Size(width, mccbEditor.MultiColumnPopupForm.Size.Height);
    }
}