Seems that a lot of people have this problem. I bought a new video card, Elsa Gladiac ultra, and with me its the same. The card only work, when I disable Background drawthread. But most of fun is, that my old matrox G 400 worked fine, but slow. E-on says, that it would be a problem with my elsa-drivers, but the nvidia reference driver wont work too. There are more problems with nvidia, maybe e-on will fix this. Niko