Having same problem and it's really annoying, I must admit. I'll try what you posted and feedback later on. Btw, I also have Ati HD 4870 and Asus (P5QL actually) I thought it was something to do with my OSX install so am reinstalling (I just started getting into osx86 yesterday) - but now I read your post it makes sense. Thanks mate! EDIT: Works wonderful - like a charm! Thanks a bunch.