When the RadTabControl is placed in a RadBusyIndicator, one of the navigation repeat buttons is initially disabled.
As a workaround, you can invoke the ScrollToHorizontalOffset method of the ScrollViewer inside the RadTabControl in a Dispatcher in the Loaded event:
The top border of the control is missing when the TabStripPlacement is set to Left Will be available in R2 2016 Release.
The scroll buttons are not correctly displayed when the TabStripPlacement is set to Right and there is no default selection (the IsDefaultItemSelected is set to False). As a workaround set the RadTabControl's IsDefaultItemSelected property to True or select a RadTabItem manually through its IsSelected property.
The tab strip is misplaced when the TabStripPlacement property is set to Left Fixed in Q3 2014
The DropDownMenu is incorrectly positioned when the default TabStripPlacement is changed - if the TabStripPlacement is set to Bottom/Left/Right, the DropDownMenuis displayed at the top left corner of the screen.
In the TabControl Databinding example, the TabControl ItemTemplate contains Button controls that has to be replaced with RadButtons.
RadTabControl with ContentPresenter replaced by RadTransitionControl brakes design time in VisualStudio 2010