Black screens when trying to play Xvid encoded avi's

[PGe]

Well I searched the forum on this but could not find an answer ...
I ran into troubles after installing a newer version of Avisynth on my system. All went OK but shortly afterwards I noticed that my Xvid encoded avi's would no longer play on BSplayer. Just a black screen and no sound (no progress neither).
So I unstalled and reinstalled the Xvid coded but this did not solve the problem. ( I use v1.1.2) Did the same with BS player (upgraded to BSplayer 2.12) but no cure . Nero vision is playing the avi fine but Echosub does not play it neither so I suspect the codec or something around it. (virtual dub can process them OK as well ...)
Any ideas ?
Thx