Hm - I'm afraid it sounds like you've done all the right things.
It is possible that you might get around the problem (with a potential performance impact) if you grab mesa3d and place its opengl32.dll in the folder with AC3D.
I'm not sure where to get a precompiled binary, though. Any chance you're a programmer (and have gcc or msvc installed)? You could grab source from
www.mesa3d.org
-- Jeff