Can anyone offer advice on this problem

Within the last week I have started to receive the following error whenever I try to preview or fix bad frames in Xvids

"The source image is not acceptable - error code -2"

I have tried using Nandub and Virtualdub MP3 but still get the same error

The actual XVids are fine and play through PowerDVD with no problems at all ( apart from the bad frames )

Anyone got a solution cos its driving me up the wall


Cheers

Fred