5.1 question using THX Optimizer from DVDs

I have a question about my XPS 400 with integrated 5.1 (with SB Audigy Advanced HD software). I know the speakers work correctly (now- they weren't yesterday) because the Speaker Test utility functions correctly. I've set up Media Center to use 5.1, and the DVD setup to use the 6 speaker configuration. When I go to the THX optimizer on a DVD (e.g., Star Wars), the channels aren't so clear cut. The sound moves around the room in general, but multiple speakers are on for each "channel". Also, the figure on the screen showing which speak is on does not move in time with the signals actually changing. This last makes me wonder if it's just a case of the optimizer not being suited for a computer application, but I'm still curious if it should work right and why it doesn't.

(The optimizers I'm using are intended for up to 7.1, which explains blending on the side channels, but even the front three channels are mixed.)

Message Edited by jkkbishop on 12-06-200608:32 PM