Today I was suprised to see a video in Totem with very strange colors. It almost looks as if one color component is missing. I was alredy looking for problems with Totem on the net, when I noticed that on the second screen of my dual head setup everything was fine. Moving the window half-way between the two screens gives me one half with the right and one half with wrong colors.
It seems to affect different players (Xine and Mplayer, too) and all sorts of video material (tried DVD, mpg and xvid).
Though I do not know for sure, I suspect the latest upgrade package that also upgraded the nvidia driver. If I do not find another solution I will try downgrading to the previous version again.