5900FX - video out - only overlay works, please help !

Hi,

I've got a bit of a problem with my GF 5900 FX : When i use the 'clone'
option with my tv-out, i can only see video playing when i turn
'video-overlay' on. When video-overlay is not on, everything works fine, but
where the video should be playing i can only see a black square.

I remember that i got the same problem with my old GF 4200 Ti, i can't seem
to find a solution to this problem on the net.

Can somebody please help me ?

Thanks !