Steam version: Entire world is dark and other problems...

[dragon1972]

I got titan quest gold off steam a while back and it worked fine when I first got it, it acted up after a while, the entire world was dark, like if you turned lighting quality to SUPER SUPER low and brightness down. When I talk to the guy who needs his horse saved the game crashes, it's completely unplayable. I fixed it that one time somehow, dont remember how, But it's acting up again, any help?

(Yes, I ran TQ before IT, I'm using the latest ati omega drivers, radeon HD 2600XT, the rest is completly fine, also, I had some driver trouble with my card before, omega fixed that.)