Re: Tearing in all video with driver 195.36.15
Do not use metacity's compositing manager. It is a software-based solution unlike compiz. It kills video playback.
Compiz on the other hand can be configured to le video playback bypass it - when i used vdpau with compiz i had no tearing (also make sure in compiz that the "sync to vblank" option is selected). Without compiz (not installed) i had tearing that was solved only by disabling the compositing extension altogether.
If you use xv for output (totem, vlc etc), do the following:
launch gstreamer-properties either in a terminal or by pressing alt+f2. Go to the video tab and select the "x window system (x11/xshm/xv)" plugin and select device "nv17 video texture" and make sure in nvidia-settings that you have selected "sync to vblank" in "xserver xvideo" settings.
Bottom line: best video playback and performance is obtained with disabling the composite extension.