No video on TV

I'm having a problem with displaying video on TV. I can see all the windows on my TV but no the video one. And some days ago i could see movies in my TV with no problem. Now, the video window is black on the TV and OK in my PC monitor, what can it be??
thanks for answering

pd: it happens the same with Windows Media Player.
Useing: ATI Radeon 7000 64MB DDR w/ TV OUT
Windows ME
Pentium 2 500Mhz
Lastest FFDShow

thanks

[Matimott]

it seems to be an overlay problem, try to use the force RGB mode options in the options, video section