I export films from Avid Liquid 7.2 into .avi format.

Sometimes when I play the .avi files, the black colour within them is displayed as dark grey instead. This happens mostly in Windows Media Player 11, but often in Power DVD, Nero ShowTime and VLC players also. When I convert the .avi files to .wmv, the same playback problem occurs sometimes.

It is as is the whole file is played out with a kind of 'lighter overlay' on top of the whole thing - as well as lightening the black colour, it apparenly desaturates the other colours too, losing their vibrancy.

I have done some research and located the TOOLS/OPTIONS/PERFORMANCE/ADVANCED/USE OVERLAYS option in WMP 11 and unchecked it... but it makes no difference upon retrying the playback.

What is most unusual, is that this issue seems quite unpredictable as to when it rears its head. I can quit out of the 'lightened' playback of a file and open it up again only to have it play perfectly. Likewise files can be playing perfectly, but upon opening them again the lightened effect returns..

It is difficult to determine if video files from other sources are affected in the same way, since I am less certain of their original depth of colouring than I am with my own Liquid-created work.

I did once have a similar problem with an earlier version of Avid Liquid [v.6], in that this strange 'lightening' phenomenon would present itself over the viewing window of my timeline. After experimenting, the output video seemed unaffected, however [when of course my media players would oblige with 'true' black playback!].

This leads me to believe there may be some kind of issue between my graphics card and Avid Liquid, but so far as I am aware there are no known problems between the software and my Nvidia 7900GT/GTO. My graphics card driver is up to date as of last week.

Anyone had this grey/black issue in media playback, and any idea where I should begin looking to stop it happening?