Under Vista, when in Basic theme, after calling IUIFramework::Destroy() the Vista theme is lost, and enlarging the window does not display outside of the initial area.
You can repro it easily with the SimpleRibbon SDK sample. In simpleribbon.cpp, insert in the WndProc switch block:
case WM_KEYUP:
DestroyFramework();
InvalidateRect(hWnd, NULL, TRUE);
break;
Compile, run, hit a key and try to enlarge in Vista Basic Theme (no problem in Win7 or Vista aero or Windows classic).
How to work around?
[edit]
I would be satisfied with some tracks to investigate, I don't expect a cooked solution :-)
[edit/] cheers, AR