http://bugs.winehq.org/show_bug.cgi?id=20448
--- Comment #11 from Henri Verbeet hverbeet@gmail.com 2009-10-26 04:02:06 --- Yes, debug output can slow things down quite a bit. If you care about performance you usually want to run with WINEDEBUG="-all".
For what it's worth, the relevant Mesa bug report is http://bugs.freedesktop.org/show_bug.cgi?id=23335. It seems there's at least a configuration issue on your side as well, since you generally want to avoid indirect rendering. Is your 32-bit libGL setup properly?