You're linking against gtk, and that probably brings in all sorts of code that can't safely be linked to in Wine. You'd probably be much happier if you carefully linked in the tiniest possible fragment of gtk needed to achieve your theming goals. (You might even be forced to duplicate a gtk source file or two, which would be a shame, but would at least give you the flexibility you need to avoid this kind of problem.)
- Dan
Are there any details about what exactly you can and cannot link into Wine? Is this due to GTK using pthreads, but Wine using its own (ie the same problem that hit Mono?).
BTW, I've also considered how you might go about making Wine apps feel "integrated" - I don't think using GTK directly is the right way though, nor using the WineLook setting.
Oh, one thing you might want to try is using the Win32 port of GTK - that way you can use the theming engines (which only use gtk -> gdi).
In particular I think it'd only be useful for WineLib apps, trying to "retheme" an application is pretty hard if it wasn't designed to look right in the native setting. So for instance it might be using GTK controls, but it won't use the pretty jimmac/tigert artwork, it'd use sucky Windows 98 style icons. In general, it'd just look wierder than with the Windows theme.
Maybe an extended window style or something.....
One possible implementation is to rearchitect wine to use the uxtheme.dll theming system that Windows XP uses. Well, it's just a random thought, but internally that might be easier than filling the control dlls with lots of GTK theme reading code.