i've the same problem with my Philipps-TV (40PFL7605H) and a HD3200 (chipset graphics). Randomly the screen turn black, 2 seconds later the picture is back, and after another second the sound comes back. It's really annoying. Especially if your watching a movie with friends...
There is NO problem with my gaming pc (Nvidia 9800 GX2). Same tv, same cable, other graphics card - everything works fine! But the AMD pc is much less noisy than the gaming machine ;-)
I would appreciate a fix in the next driver release, because i can't life with that :-)
If you need more information, feel free to ask!