ATI driver problems: 7.12 and 8.1

[burbble]

The short version is that version 7.11 of the ATI drivers and Catalyst center seem to be the latest that function correctly with Penumbra on my system (Radeon X1650XT). 7.12 and 8.1 have problems.

Long version:

I downloaded the demo for Black Plague a few days ago, and the opening screen of the game (where you wake up looking at the ceiling and fluorescent light) had bizzare graphical anomalies (the textures were twitching and jumping as the camera moved). Some of the errors would not reappear when you looked at the same spot again. Looking around would sometimes reveal other anomalies that would be distorted and then suddenly go back to normal.

The tutorial also had strange anomalies, the most obvious being the blood splatter on the ground was flickering (e.g., looked 50% transparent because it was only showing up every other frame).

I loaded Penumbra Overture, and it suddenly developed the same problem (I played through the game with no issues a few months ago). The wall with the portholes had a strange texture that would not move with the camera, had about 16 porthole-shaped blue circles that stretched at an angle, and eventually went away once you looked at it enough.

Turning off Post Effects solved the majority of the graphical issues (all but a couple flickering or incorrectly-lit textures here and there), but also disables Bloom (which looks so good!). This was with version 8.1 of the ATI driver and Catalyst center.

I uninstalled the video drivers and installed version 7.12. Same problem. Uninstalled again, installed version 7.11, and the problems are gone (both games run flawlessly as Overture did when I first played it). If I put either new version of the drivers back, the problems reappear.

I have no idea what has changed with the OpenGL portion from version 7.11 to 7.12, but whatever it is seems to break Penumbra. Since downgrading to older drivers is more like a temporary fix, I thought I'd post this so that it could be looked into.

For reference, my video cards are two Radeon X1650XT in Crossfire. I have access to a system with an X1950XT, but haven't tested whether it experiences the same problem (I can if you think it would be useful).