I have downgraded my xserver-common packages and I still have the problem. Lets try to narrow it down. I am 99% sure its an xv scaler problem, since i can view videos in vesa and aalib with no lines. I had the problem fixed for a while when I downgraded to 3123, but as I said before when I upgraded xserver-common the problem came back.
1. The upgrade changed my XF86Config-4, so there may be some obscure setting there that fixes it.
2. I had also recompiled my kernel, because my old kernel was compiled with an older gcc, now im using 3.2.2. When fullscreen was working without lines I was using linux 2.4.20 compiled with i think gcc 2.9.6 and the 3123 drivers which worked were also compiled with that version. So it may be a build problem?
3. problem with something in xv scaler in the xserver package that wasnt erased when i downgraded?
Thats all i can think of at the moment. Again, the weird weird weird thing is that if i open up 2 movies the scaler will work on the 2nd and it will scale fine with no lines. As long as xv is already running it seems the scaler works, but not on the first try
I have also tried 4 other sets of older nvidia drivers and all of them have the scaling problem. The problem appears in ogle, mplayer, xine, aviplay etc. so its definately a driver and/or xv scaler problem.