Just wanted to add myself to the list of people having this problem.  Everything else is working just fine, I can play back video, etc., but when I launch live TV I just get a black screen.  My mouse pointer is the only visible thing.

Here are my computer specs:

- opteron 165
- ATI 9800 pro (output only, using UI1)
- hauppauge pvr-150 tuner (x2)

I thought it might have something to do with the TV / resolution I was outputting to, so I plugged into my LCD computer monitor and increased the resolution.  However, I had exactly the same problem.

If anyone has a solution I look forward to hearing it.