I have a WPF page with the following configuration:

Stack Panel

-> Read-Only Grid | Read-Only Grid | Read-Only Grid

StackPanel

-> GridSplitter

StackPanel

-> Editable Grid | Editable Grid

If the user enters a row in either of the editable grids they are able to tab to the next cell but not edit the contents.  I see the active cell highlighted so I know it has focus.  If I click on the cell I am able to edit the contents.  This only affects the plain text (XamTextEditor) cells.  The cells with a calendar control do correctly enter edit mode when you enter them via tab.

Am I not able to have two grids in edit mode at the same time on the same page?