GridViewColumnGroups.Header does not respect any content different from string when EnableColumnGroupsVirtualization is True.

*** Workaround: Use HeaderTemplate property instead or set EnableColumnGroupsVirtualization to False in all themes different than Windows8, Windows8Touch and ExpressionDark.

The problem should be resolved with version Q2 2015 SP1.

GridViewColumnGroup.HeaderTemplate is not respected in Windows8, Windows8Touch and ExpressionDark themes. Instead, the name of the column group is its content.

This is reproducible with both StyleManager and Implicit Styles.

Should be resolved with lib version 2015.2.720.

The problem can be reproduced only when the previously focused element is in ToolBar or RadToolBar. It is not reproducible in the default scenario. 

Should be resolved with lib version 2015.2.713.

А new virtualization mechanism for ColumnGroups will be introduced with Q2 2015. A property EnableColumnGroupsVirtualization is exposed with default value True for enabled virtualization. Setting it to False will enable the old logic.

The fix will be available with Q2 2015.

Just run the attached project and scroll horizontally to the very end several times (at least two times).
I tried disabling the column virtualization but this did not help.

This issue will be resolved with Q2 2015. 
A new virtualization mechanism for ColumnGroups will be introduced with Q2 2015. A property EnableColumnGroupsVirtualization is exposed with default value True for enabled virtualization. Setting it to False will enable the old logic. 

This problem is reproducible only in WPF and can be observed on both Row Context Menu and Header Context Menu QSF examples.

The fix will be available with Q2 2015 version.

Focus stops moving but selection keeps moving when navigating through the keyboard down key. When the window is stretched so that the ScrollBar is not visible, the issue could not be reproduced.

GridViewDataColumn.IsVisible binding is broken in a custom scenario. The problem is reproducible only in child GridView.

It should be resolved with lib version 2015.1.504.

When you place a DataTrigger whithin a CellTemplate, it is being ignored by RadGridView for WPF

Workaround ( until fixed ) - set the ContentTemplate of the cell via Style in a static resource instead.