Blu-ray PC Issues

[Renegade]

Hey folks. Its nice to be a part of the blu-ray world... Watched one Blu-Ray and decided I want to stay, but I am having trouble with that part. The first (and only) Blu-ray that I could run on my PC was "The Departed." It worked without a hitch, but since then, I have had absolutely no luck with any other Blu-ray.

I've tried a handful of things like emulating the Blu-Ray by making an ISO of it. Using this method, I can get an ISO for all my movies (except SWAT) on my harddrive and successfully mount them. Again, The Departed is the only one that works.

Because "The Departed" plays, I temped to say that the software is the problem, not the hardware... But just incase, this is what I am currently running.

Processor: Intel Q6600
Mobo: EVGA nVidia nForce 780i 132-CK-NF78-A1
GPU: MSI 8800 Ultra (660 MHz core clock, 2300 MHz memory clock)
Ram: 2GB DDR2 667
HDD: 2x Western Digital 260GB in RAID 0, 1x Western Digital 500GB, 1x Western Digital 750GB
BD Drive: Lite-On DH-4O1S-08 (With newest firmware)
Display: Hanns*G 28" HD LCD (Native to 1920x1200)

I do a lot of research on PC components, so Im fairly certain what I have should run Blu-Ray without a hitch... Given that I just installed the latest PowerDVD and nVidia drivers, what do you think I should do next to get all this working properly?

Thanks in advance for your help!