ATI 4850 graphical issues - K1 unplayable, glitches in TSL

[DarthParametric]

I bought a Radeon HD 4850 a couple of months ago to replace my aging Geforce 6800. I installed TSL again last week and I noticed a couple of graphical issues with it. The first is that whenever I use Burst of Speed, the on-screen blur effect is completely messed up. Most of the time it ends up like a mosaic effect, although other times it looks different. [EDIT: Seems like there is a known bug with KOTOR's framebuffer effects and the newer ATI cards that causes graphical corruption.]

 

While that is annoying, I can live with it. When I decided to install K1 tonight to test a mod however, I hit a real show stopper. During the character creation process, the whole screen will become corrupt. The first time it became almost a solid pink. The second time it became a series of brownish vertical stripes. Alt-tabbing out of the game doesn't fix it either - you have to do a hard reset.

 

Seeing as both games ran fine on the exact same hardware with a Geforce 6800, I can only assume that the issue is driver related. Something to do with OGL perhaps? I've tried both Catalyst 8.8 and 8.9 (the latest), but the issues occur on both. Anyone got any thoughts or suggestions? Especially as to why TSL doesn't get as badly affected as K1 does?

 

EDIT: Tried turning off ATI AI which I saw suggested in a thread for someone having issues with a 4850 in Neverwinter Nights. Didn't make any difference. I ran K1 fine on my laptop (which has a Geforce 7600 mobile) to test a mod and I noticed in the specs listing that the OGL version is around 2.0. I wonder how significant that is.

 

EDIT 2: Just tried to start a new game in TSL and ran into the same issue I was getting in K1. Got to the point of entering a name for a new character and boom. Looks like what is happening is the card stops responding. A hard reboot is the only way to get it to recover (the VPU Recover feature of the Catalyst Control Center is just an endless loop - never recovers). The weird thing about this is I have been playing TSL fine for the last couple of weeks, aside from the graphical corruption issues mentioned above. I guess something happens during character creation that causes the card to wig out. I'm going to try some saves I made on another machine for both K1 and TSL right after the intros and see if they work.

 

EDIT 3: That worked. Can play both games starting from a save made on another machine without hitting the same sort of bug that's in the character creation menu. It's really just that bit that is causing me grief. It's a serious PITA, but at least there is a workaround. If anyone has some insight to what's causing the issue (and potential solutions), I'd appreciate hearing about it.