think i found the problem. would somebody try to install speedx 3d?
brood, did you play around with cache sizes?
/cache is only 4 mb big. i mean it's not 4 mb free, but it's 4 mb altogether. on stock rom its about 100mb big. so if market caches downloads in /cache, then its no wonder i can't install apps bigger than 4 mb and nobody else should be able to do so either.
Just install Speedx 3d via Market. It works fine for me.