[vdr] Improving quality of xvideo output for vdr-sxfe

I know this is slightly of topic but I am not sure where else to turn.

I am using the binary drivers from nidia on a GeForce 5500 graphics card. I have two cables plugged into it, one dvi to vga adapter which is plugged into my flat panel tv then other a normal vga cable plugged into a flat panel screen. Both screens are mirrored on 1280x1024.

The effect I have is that overlay XV displays appear to cut and tear in both mplayer and vdr-sfxe.

If I use the xvmc driver then I don't get a video overlay (ie, no menus) although the quality is much better.

There are no strange options that I can see if xorg.conf.

Can anyone recommend anything I can try?