GeForce and plasma TV 1080p video playback

[and_woox]

I have a 1080p plasma TV connected to a GeForce FX 5500 thru an DVI to HDMI adaptor and a hi speed HDMI cable.
The TV is set to 1920X1080 resolution (1080p) under Windows and it display the desktop perfectly, but when any video playback is started (SD or HD) the TV starts to flicker and then says that there is no DVI/HDMI connection made. If the the video playback is stopped using the keyboard the picture of the paused video shows on the screen until the video playback is resumed.
If any other resolution is set under Windows everything goes fine.
Do you know what could be happening?
Thank you

 

[Grador]

Can you specify what software you are using, and what type of video files/disks you are playing?

 

[and_woox]

Thank you for the reply.
I have tried VLC, Media Player Classic and a few others to play any video file(avi, mpg, a file from a digital camera...).
When i play any video file (only changing the display resolution on Windows) they all display fine on the TV.

 

[its phillip]

maybe the card isn't hdcp compliant? just a guess.

 

[Grador]

Without looking at the system I'm at a loss as to what it might be, but I doubt it's an HDCP issue as that would only affect content that required it, and not all files.