WinXP cannot play movies on TV

Hallo,
I have P4 1.8, 512 and graphic card NVidia Geforce 2MX. When play movie by Windows Media Player under Windows 2000, it can be easily transfer to TV (TV out composit port) through Clone/Twinview from NVidia without any problem. But under Windows XP, movie can not be shown on TV although the destop screen still appear. The windows of WMPlayer is black. I try to download the newest driver from NVidia (56.72 winxp2k international_whql) for all GeForce card with integrated nView management. All is OK except Clone view (Monitor + TV). I try to use dublicate function, then I drag WMPlayer to the TV screen. It works but when I maximize to full screen, the screen on TV is black again and the film screen jumps back to the computer screen. Could you help me solving this problem? Is this the problem from the nVidia under XP?
Thanks in advance,

This may well be a digital rights problem.

Some dvds are coded so that they will not play on a computer with TV out.

Do you have all your windows updates done? Media player updates too? (they are not in the critical section).