When applying a filter to RadGridView, there is inconsistency between underlying data source current row and grid's current row.

If there are DateTime values less than "1900-01-01", the exported file cannot be opened from MS Excel because it does not support them. 

To Do: a warning for invalid excel values before exporting.

When exporting to excel through ExportToExcelML class, Guid type values are not exported.

DateTimeColumn should open hitting the F4 key. 

WORKAROUND:
this.radGridView1.EditorRequired += new EditorRequiredEventHandler(radGridView1_EditorRequired);

void radGridView1_EditorRequired(object sender, EditorRequiredEventArgs e)
        {
            

To reproduce: - add couple columns in design time - populate them in the form's constructor - subscribe to the cell formatting event where validation will be performed The result is that the indent cell hover displays the error text set and the data cells are formatted correctly, but the exclamation mark is not displayed until the grid is scrolled. It seems that the indent cell is not invalidated
WORKAROUND: Call the Refresh method of the template

Assigning a custom type convertor to the column's DateTypeConvertor property does not work as expected.

Add error provider for AddNewRow element and options to show validation error icon and text.

IIF function in Expression for calculated columns does not work.

Typo error - "Lenght" instead of "Length", located under "Text" in the GridView expression editor

On DateTime column when IsNull or IsNotNull option has been chosen it throws exception.

When changing parent form Localization property the column's header text does not changes appropriately

Add support for filtering guid type of values

Add support for pinning multiply selected rows at once.

Steps to reproduce:
1) Add RadGridView control
2) Use GridViewDecimalColumn:

        DataTable customDataTable = new DataTable();
        sampleDataTable.Columns.Add("Column name", typeof(double));

3) Set the right-to-left property of the control to true:

        this.radGridView1.RightToLeft = System.Windows.Forms.RightToLeft.Yes;

4) Set the following CellElement properties using CellFormatting event:

        void radGridView1_CellFormatting(object sender, Telerik.WinControls.UI.CellFormattingEventArgs e)
        {
            if (e.CellElement is GridDataCellElement)
            {
                e.CellElement.RightToLeft = false;
            }
        }

5) Re-size the form manually until the horizontal scroll-bar disappears
6) Resize a GridHeaderCellElement in left direction and you will notice that the GridDataCellElements from this columns are resized to the right direction

Whenever I'm trying to expand any column the header expands as expected but the column itself is expanding in the other direction so the headers and columns content are not aligned. 
Expected result: expand the column content properly
Actual result: the GridDataCellElements from this columns are expanding incorrectly

When adding a new row in underling data source and SelectLastAddedRow is true the newly added row is set as current but it is out of visible grid area.

Extend the support of Translucent Selection Rectangle on pinned rows.

CellFormatting should not me thrown for filter cell elements.

Add an API for easy switching to sort by DisplayMember in combo-box column.