There is a known issue about freezes on silicon motion. I was never able to reproduce it, therefore I have no fix for it. However there is a workaround: Either turn off write combining for the framebuffer by putting Option "NoMTRR" into the device section of the XF86Config. Or reduce the size of the video RAM used by the chip by Putting: VideoRam (where you have to replace with an actual number in kB). Unless there is another problem I don't know about, yet, this should help. -- Egbert Eich XFree86 Core Team Member SuSE Linux AG eich@xfree86.org eich@suse.de