Artefacts With A 9800se Running 3d Applications

Hi to all. Tha is my first mail to this mailing list. I'm really a newbie with Linux. It looks like that i have installed with sucess the Ati drivers 3.9.0., with Suse Linux 9.1. But when i run any 3D application, the image have "artefacts". Any one knows why this happens and how can i resolve this problem? Thanks. Cláudio Oliveira from Portugal