Odd, i have this app where one of the controls is using 2 theme handles.
The dialog as in DDT modus as in SDK modus will give a white back color when from XP theming to classic mode.

A simple DDT dialog without any controls does not show this behaviour..

I am using OpenThemeData() on the same hWnd however i need to paint two different controltypes.
Painting itself goes fine.

?