Pushbutton and other controls in C# Framework 1.1 dlg does not skin. C++ ok. Why?

I made a very simple dialog-based C# program with a few pushbuttons and no other controls. The problem is that the buttons won't skin (the frame skins correctly). I have tried to change the button type from standard to system, and a few other button attributes, nothing works.I also put a slidebar in the dialog to see if the problem was related to the control type. It did not skin either. I have tried all the skins in that comes with Skin studio (and some downloaded). The same program in C++ (MFC dialog) skins correctly. The Skin studio/Window blinds 5.01 werw purchased this week.
/Håkan (Sweden)