How to reproduce:
-embed WPF content in a Win32 application as described in the msdn topic
"WPF and Win32 Interoperation Overview".
- press the TAB key inside the WPF content to move from one control to
another.
- expected: the style described by the property FocusVisualStyle would be
rendered to indicate keyboard focus (usually it's a dashed rectangle).
- observed: keyboard focus is not rendered.
This problem can be noticed in the msdn sample "Hosting Windows Presentation
Foundation Content in a Win32 Window" by navigating using the keyboard to one
of the WPF buttons.
NOTE: If the same WPF content is placed as the Content of a Window, then the
keyboard focus is rendered properly.

Is this a known bug? Is there any documented workaround?