Strange Behaviour of wxBitmapButton

[Björn Fabritius]

Happy New Year to you all!

New year, same work ;)
I placed 5 wxBitmapButtons on a Panel showing (of course) different bitmaps 
loaded from xpm-files. When the frame containing the panel is first shown 
all buttons have the same bitmap, which is always the last one I've loaded. 
Only after a forced repaint (by minimizing/maximizing the frame for example) 
are the bitmaps shown correctly.
I tried different solutions after the control placement like hide/show or 
update, but to no avail.
Is this a MSW-problem or is there a workaround? I also couldn't find a 
sample which uses wxBitmapButton.

I use wxWidgets 2.6.3 with MSW and VC++

regards
Bjoern