Playback Issues

[Voyager]

Hi guys, I'm having problems with Season Two of The BSG Complete on Blu-ray. The first, third, and fourth season (with the exception of Razor) worked correctly. I have watched Season One all the way through and all the episodes played normally. Season Two starts to lag (or act choppy) as soon the Blu-ray logo pops up. The menu is all laggy as is the video in the background. Audio is fine. I am using Cyberlink PowerDVD 9 Ultra to play and the BD Adviser says that everything is ok for playing Blu-ray with the exception of an "Upgrade" for Hardware Dual-Video Decoding for all three under the advanced tab. I am unsure what to do. I have already received a second set and it does the same thing.

Specs:
Windows 7 RC 64-bit
AMD Athlon 64 X2 Dual 4600+ 2.4GHz
GeForce 9800 GT 1GB
4GB of System Mem
LG GGW-H20L

All drivers are up to date.