- Tearing can occur on some systems that don't properly support triple buffering. Just don't activate d3d_triplebuffer and you won't have tearing. So I consider this not a real problem.

- Your description of visual artifacts does not sound like a driver problem. It sounds more like a hardware problem either of your 3D card, your power supply, or the AGP port. Problems of this sort are indeed hard to determine because they only occur under certain circumstances. I'm afraid I don't have a ready solution regarding this problem.

I'm moving this thread to the engine forum. Maybe another user has had a similar problem and can share his experiences. Posting a screenshot and some more info about your problem could help.