When you drag a RadDateTimePicker from the Toolbox and drop it onto the form, the TabStop property is false by default. If you change it in the Properties grid to true and save the form, try to open the form designer again. As a result the TabStop property is set to false as if no changes have been performed.

Use attached to reproduce.

Workaround:
RadTextBox tb = new RadTextBox();

tb.Font = new Font(Font.Name, 12F, FontStyle.Bold);

tb.MaxLength = 200;
tb.Name = "textBox1";
tb.Text = "<Required>";
tb.Location = new Point(49, 7);
var pixels = tb.Font.SizeInPoints * 96 / 72;
tb.TextBoxElement.TextBoxItem.HostedControl.MinimumSize = new Size(0, (int)pixels + 6);

To reproduce: please refer to the attached sample project and gif file.

Workaround: this.radTextBox1.MinimumSize = new System.Drawing.Size(0, 25);
or
Use RadTextBoxControl

Workaround: 

public RadForm1()
{
    InitializeComponent();

    this.radSpinEditor1.SpinElement.TextChanging += SpinElement_TextChanging;
    this.radSpinEditor1.TextChanged += radSpinEditor1_TextChanged;
}

private void SpinElement_TextChanging(object sender, Telerik.WinControls.TextChangingEventArgs e)
{
    int numericValue = 0;
    if (!int.TryParse(e.NewValue, out numericValue))
    {
        this.radSpinEditor1.Tag = e.OldValue;
        e.Cancel = false;
    }
}

private void radSpinEditor1_TextChanged(object sender, EventArgs e)
{
    if (this.radSpinEditor1.Tag != null)
    {
        this.radSpinEditor1.SpinElement.Text = this.radSpinEditor1.Tag.ToString(); 
        this.radSpinEditor1.Tag = null;
    }
}

The Free Form Date Time Parsing of a RadTimePicker is not able to recognize "hhmm" as an legit value (ex. 1030 for half pas ten).

This improvement could be nice, as it is a common way to write an time. It is working in Outlook Appointement Form.

to reproduce this bug :
add RadDateTimePicker and set culture to fa-IR
change the header navigation mode to zoom with : 
Me.radDateTimePicker1.DateTimePickerElement.Calendar.HeaderNavigationMode = HeaderNavigationMode.Zoom
popup the date time picker then georgian dates are displayed
i'll attach screenshots of what happening.

To reproduce: add a RadTreeView and a timer. Use the following code:

BindingList<Item> list = new BindingList<Item>();

public Form1()
{
    InitializeComponent();
    this.radTreeView1.TreeViewElement.CreateNodeElement += TreeViewElement_CreateNodeElement;
   
    for (int i = 0; i < 10; i++)
    {
        list.Add(new Item(Guid.NewGuid().ToString(), "Node" + i));
    }

    this.radTreeView1.DataSource = list;
    this.radTreeView1.DisplayMember = "Title";
    this.radTreeView1.ValueMember = "UniqueIdentifier";

    this.radTreeView1.TreeViewElement.AutoSizeItems = true;
    this.timer1.Start();
}

void TreeViewElement_CreateNodeElement(object sender, Telerik.WinControls.UI.CreateTreeNodeElementEventArgs e)
{
    e.NodeElement = new CustomTreeNodeElement();
}

public class Item: System.ComponentModel.INotifyPropertyChanged
{
    public Item(string uniqueIdentifier, string title)
            {
                this._uniqueIdentifier = uniqueIdentifier;
                this._title = title;
            }

    public string UniqueIdentifier
            {
                get
                {
                    return this._uniqueIdentifier;
                }
                set
                {
                    this._uniqueIdentifier = value;
                    OnPropertyChanged("UniqueIdentifier");
                }
            }

    public string Title
            {
                get
                {
                    return this._title;
                }
                set
                {
                    this._title = value;
                    OnPropertyChanged("Title");
                }
            }

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
            {
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
                }
            }

    private string _uniqueIdentifier;
    private string _title;
}

public class CustomContentElement : TreeNodeContentElement
{
    StackLayoutElement nodeContentContainer;
    LinePrimitive lineElement;
    LightVisualElement idElement;
    RadTextBoxControlElement textBoxElement;

    protected override Type ThemeEffectiveType
            {
                get
                {
                    return typeof(TreeNodeContentElement);
                }
            }

    protected override void InitializeFields()
            {
                base.InitializeFields();
                this.Margin = new Padding(5, 5, 5, 5);

                this.StretchHorizontally = true;
            }

    public override void Synchronize()
    {
        this.DrawFill = true;

        TreeNodeElement treeNodeElement = this.NodeElement;
        RadTreeNode node = treeNodeElement.Data;
        Item dataItem = (Item)node.DataBoundItem;
        if (dataItem != null)
        {
            this.idElement.Text = string.Empty + dataItem.UniqueIdentifier;

            this.textBoxElement.Text = string.Empty + dataItem.Title;
        }
    }

    protected override void CreateChildElements()
            {
                nodeContentContainer = new StackLayoutElement();
                nodeContentContainer.Orientation = Orientation.Vertical;
                nodeContentContainer.StretchHorizontally = true;
                nodeContentContainer.StretchVertically = false;

                idElement = new LightVisualElement();
                idElement.ShouldHandleMouseInput = false;
                idElement.NotifyParentOnMouseInput = true;
                idElement.StretchVertically = false;
                this.nodeContentContainer.Children.Add(idElement);

                lineElement = new LinePrimitive();
                lineElement.BackColor = Color.Black;
                lineElement.Margin = new Padding(10, 0, 10, 0);
                lineElement.StretchVertically = false;
                this.nodeContentContainer.Children.Add(lineElement);

                textBoxElement = new RadTextBoxControlElement();
                textBoxElement.TextChanged += textBoxElement_TextChanged;
                textBoxElement.Margin = new Padding(20, 3, 20, 3);
                textBoxElement.StretchVertically = false;
                this.nodeContentContainer.Children.Add(textBoxElement);

                this.Children.Add(nodeContentContainer);
            }

    private void textBoxElement_TextChanged(object sender, EventArgs e)
    {
        RadTextBoxControlElement tb = sender as RadTextBoxControlElement;
        CustomContentElement contentElement = tb.Parent.Parent as CustomContentElement;
        Item item = contentElement.NodeElement.Data.DataBoundItem as Item;
        if (item.Title != tb.Text)
        {
            item.Title = tb.Text;
        }
    }
}

public class CustomTreeNodeElement : TreeNodeElement
{
    protected override TreeNodeContentElement CreateContentElement()
    {
        return new CustomContentElement();
    }

    protected override Type ThemeEffectiveType
    {
        get
        {
            return typeof(TreeNodeElement);
        }
    }
}

private void timer1_Tick(object sender, EventArgs e)
{
    foreach (Item item in list)
    {
        item.Title = "Node " + DateTime.Now.ToLongTimeString();
    }
}

To reproduce:
-Add RadBrowseEditor to a form and set the DialogType to FolderBrowseDialog.
-At runtime click the browse button to open the "Browse For Folder" dialog and click the "Make New Folder", type a name for the newly created folder BUT DO NOT PRESS THE ENTER KEY and click the OK button, the Value is set to "New Folder" instead of the name I have typed.

Currently, when Delete is pressed the min values is set, however, the textbox should be cleared. 

This can be handled by using a custom provider:
public class MyFreeFormDateTimeProvider : FreeFormDateTimeProvider
{
    public MyFreeFormDateTimeProvider(string mask, CultureInfo culture, RadMaskedEditBoxElement owner)
        : base(mask, culture, owner)
    { }
    public override void KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyValue != 46)
        {
            base.KeyDown(sender, e);
        }         
    }
}

When you set a specific value to the RadTimePicker e.g.  new DateTime(2014, 5, 20, 8, 15, 30) and try to change the time via mouse wheel or up/down arrows, the date part is reset to DateTime.Now.

Resolution: 
This broke RadTimePicker functionality because many users have serialized in designer.cs/vb files MinValue and MaxValues and now they date part is take  under consideration - this can complete broke its application. Users should keep the date part in separate variable not in TimePicker Value property

Allow RadSpellChecker to perform check spelling for many controls.

Reason for denial: 
The RadSpellCheker knows the associated document and for example if a user presses ignore all (in as you type) this should be ignored only for specific documents. 
Also spell checker is inherited from MS component named 'Native Windows' which allows spell checker to receive a WND messages from the associated control.

Description:
RadMaskedEditBox (with MaskType=Numeric and Mask = "c") is bound to a property of type decimal. If you type in 15 it goes into the maskedEditbox as 51.

Reproduce:
-add a BindingSource (DataSource is set to some data table: for example "Products")
-add a BindingNavigator (Binding Source is set to the previously added bindingNavigator1)
-add a RadMaskedEditBox (with MaskType=Numeric and Mask = "c") with DataBindings: Value => bindingSource1 - UnitPrice
-add a new record using the yellow plus sign button in the navigator; get to the price field and just start typing your number: if you type in 15, it goes into the RadMaskedEditBox as 51.

Workaround:
Bind to Text instead of binding to Value of the RadMaskedEditBox

this.radMaskedEditBox1.DataBindings.Add(new Binding("Text", bindingSource1, "UnitPrice", true));

Resolution: 
RadMaskedEditBox with currency mask does not support null values. Default value must be 0 instead null. Please use the following code snippet: 
this.mePrice.DataBindings.Add(new System.Windows.Forms.Binding("Value", this.bindingSource1, "Price", true, System.Windows.Forms.DataSourceUpdateMode.OnPropertyChanged, 0, "C2"));

When a user selects a known color, the SelectedColor property returns an RGB value instead of the known color.

Resolution: The Color.Name, IsNamedColor and IsKnownColor properties are set properly. 

To reproduce:
-add RadDateTimePicker and apply Windows7 theme
-enable calendar footer
-when opening the drop down calendar, the date part in the footer is not displayed correctly

Workaround:
 RadDateTimePickerCalendar calendarBehavior = 
     this.radDateTimePicker1.DateTimePickerElement.GetCurrentBehavior() as RadDateTimePickerCalendar;
 RadCalendar calendar = calendarBehavior.Calendar as RadCalendar;
 calendar.ShowFooter = true;
 calendarBehavior.PopupControl.PopupOpening += PopupControl_PopupOpening;

private void PopupControl_PopupOpening(object sender, CancelEventArgs args)
{
    RadDateTimePickerDropDown popup = sender as RadDateTimePickerDropDown;
    if (popup != null)
    {
        popup.Height = 250;
        popup.Width = 280;
    }
}

Currently it is not possible to represent time as 24:00 in time picker control as it uses the .NET DateType type, which does not support "24:00" as valid time.