Greetings:

Using my HP HDX9494NR desktop replacement, I am able to watch the BluRay Hulk movie on my HDTV (TH-50PX77U) using the latest Quickplay 3.7 (I think it's an HP custom PowerDVD) and the sound comes out thru my 7.1 receiver (Denon AVR-4806) and 7.1 speakers system via the HDMI laptop port. However, the sound is decoded in stereo instead of 5.1 DTS even though the movie menu setting shows 5.1 DTS as default.
If I go to the advanced tab in QP, the options are only 2 channel 44.1, 48, 88, KHz etc. I try different frequencies but the optimal sounds is the 44.1KHz. I wonder if this is normal.
I also update to the latest audio driver dated 08/2008 (the old one is dated 07/2007) to no avail.
The sound is decoded correctly as DD, DTS etc if I use DVDs instead of BluRay. In other word, for some reason QP does not decode the sound properly only in BluRay. As for WinDVD 9 and AnyDVD 6.4.7.9 is not a viable solution since the movie is jerky. The sound is decoded correctly as 5.1 DTS but the movie is unwatchable since the movie frames froze and unfroze frequently.
Any idea what I might be missing?

Thanks in advance for your time and help.