doccarnby: Well, I figured that this would be a good place to ask, since the community here is likely to know the answer.
Anyway, I upgraded my drivers (ATI Radeon Xpress 1250, I know) and since then in Myth 3, particle effects like blood, smoke, and fire, all show up as big, single flat colored squares, and is really quite annoying. I was wonderiong if anyone had any suggestions, hopefully ones that don;t involve downgrading my drivers.
Myth 3 is running with the 1.3.1 patch, with all the settings as high as they will go. Can anybody help?

thelovebat: You could try running it in compatibility mode and/or as an administrator.

Stelis: What version?

Do you use the amd site or windows update?

doccarnby: I'm not certain what version, the latest, I think, but I'm not sure. I used the AMD site, though. Where do I check the driver version?

Stelis: Open the catalyst control center.

Stelis: OK. You have the latest driver for your card.

Now, go to Catalyst Control Center (not basic view) and under 3d settings disable catalyst AI.

Then check to see if the problem is fixed.

doccarnby: That did it, thanks!