http://bugs.winehq.org/show_bug.cgi?id=28078
--- Comment #10 from Henri Verbeet hverbeet@gmail.com 2011-08-17 07:23:23 CDT --- (In reply to comment #9)
No need to bother about (2), I have my suspicion now. I guess that the game draws transformed geometry(x/y/z/rhw position), where the rhw doesn't influence the vertex's position, but affects texturing. Without converted vertex buffers we ignore the rhw(reciprocal w) because opengl expects x/rhw, y/rhw, z/rhw, 1/rhw. This is could be considered a performance hack.
Using VBOs or not shouldn't make a difference. Without VBOs you're supposed to go to the immediate mode path and do the same fixup there.