@ Peter: Actually, today's update (sorry, don't know which package) fixed things with Totem Movie Player, but xine was still reporting segmentation faults, so I installed the mainline kernel and, indeed, it completely fixed the video problems. Thanks for pointing that out again!
Unfortunately, I still have problems using an external monitor, but that might be a quite unrelated bug. I can switch the external monitor on, but not off, and inevitably things crash/freeze when I'm changing Monitor settings.
@ Peter: Actually, today's update (sorry, don't know which package) fixed things with Totem Movie Player, but xine was still reporting segmentation faults, so I installed the mainline kernel and, indeed, it completely fixed the video problems. Thanks for pointing that out again!
Unfortunately, I still have problems using an external monitor, but that might be a quite unrelated bug. I can switch the external monitor on, but not off, and inevitably things crash/freeze when I'm changing Monitor settings.