When I bought my PCTV HD Pro Stick USB tuner it came with an older version of TVCenter so I updated to the lastest version I could find on the Pinnacle website only to find that the program is still extremely buggy.  In fact I would have to say it's one of the most glitch infested programs on my computer.

 I'm running Windows XP Pro SP2 on an ASUS Crosshair motherboard with an AMD Athlon 64 x2 Dual Core Processor 4600+, 4GB of RAM, and an Nvidia GeFore 8600 GT VGA card.  I have no problems receiving over the air HD broadcasts but the software just doesn't respond well as a user interface.  When I double click to go to full screen and the bars auto hide, remnants of the buttons still show.  Sometimes when I double click on it to make it go back to a window it doesn't, it just shifts the full screen window to one corner.  Occasionally the audio goes out of sync with the video.  I just can't figure out how this program can be up to version 4.98 and still not work right.

I really think this is because Pinnacle is using a bunch of robots who do not watch TV to develop the PCTV program

We're in the same boat. They assured me that upgrading to 4.98 would solve most of my picture/audio problems. If anything, they've gotten much much worse.

I can't reproduce this problem. Have you tried using a more recent version of the driver for the grafics card (from nvidia.com)?

Could you, just for testing, reduce your RAM to 1 or 2 GB and see, if the problem still occurs?