REALLY horrible blue ray playback.

[jmg]

Just added totalmedia to my HTPC, and got my first blue ray from netflix.
the playback is HORRIBLE-- very choppy and laggy. MY question (before anyone reads my stats and says "replace the cpu) is whether I can work with the system I have.. I just finished upgraded it, and I really don't feel like dropping in another mobo/cpu, even if its a cheap dual core:

HEre are my stats:

Pentium M 780 (2.26 ghz)
aopen i916ga-hfs mobo (in an HTC case-- not a laptop)
4 gigs ram
LG blueray /hd sata drive (ggc-h20l)
120 gig PATA drive (boot)
1.5 terrabyte SATA drive (storage and page file)
nvidia 7950 GTS w/ 512 meg
windows ultimate
totalmedia theatre in windows media center

Before anyone hits the "reply" button, I *KNOW* the cpu is a little dated. I also know that the card is dated. When I run the test program from powerdvd, everythign passes, with the obvious yellow light on the CPU.

During playback (using totalmedia in windows media center), playback is horrible. Same in powerDVD. My CPU is getting THRASED (hardware accleration is selected). I have latest drivers for everything, and am going to drop in an EVGA overclocked NVIDIA 8800 GTS.

My question is, is there ANYTHING I can do to salvage this? Memory is fine, I'm not even getting close to running out. The drives are really fast, and given that the page file is on the brand-new fast SATA drive, I can't imagine it's adding to the problem.

Will upgrading the video help?
Is there anything I can look at to stop the bleeding on the CPU? The minimum requirements for blue ray playback from a pentium M was a 2.0 ghz chip.. and I totally remember being able to run blue rays from the old pentium m laptops when the blue rays came out.

Suggestions (again, please, don't tell me to get a new mobo/cpu).

Thanks!