Fx5200 card only shows video in 16 colours

I've installed a GeForce FX 5200 card in my PC and the installation went
fine, however, when I run any type of video clip (avi, mpeg, real,
Quicktime) in any player, the video looks washed out and appears to be
running in something like 16 colours. The normal screen display is fine in
either 16 or 32 bit.

I deleted the driver and rebooted the machine and tried running the video
with the default Mickytsoft driver and the video displayed fine, so its
something up either with the Nvidia driver or I'm missing something in the
settings.

Any help appreciated!!

Martin