The problems weren't for everyone, but they were very wide-spread, and random, I know my setup isn't the greatest for the game, but a bunch of users with high-end systems had problems as well, it's all known by R*, but from everything I've read, they were either not going to fix it, or couldn't.
The problems are poor performance basically.
I run a gf2, etc (in sig), so the game isn't the nicest, while running at 800*600, everything turned off, friend of mine has a 1.1 athlon, gf3 ti500, runs nice at high rez and everything maxed, though some with similar procs, through high-end xp's and p4s, and top-end gf3's and 4's, as well as radeons, have similar gameplay that I have.
All I can hope for is that I don't have that luck once I'm done with all my upgrades.