Unable to play DVDs (1 Viewer)

[npoenn]

TV-Server Version:
MediaPortal Version: 1.0.0.0 RC2
MediaPortal Skin: Blue Two
Windows Version: XP Pro SP3
CPU Type: AMD Athlon 64x2 5000+ 2.6GHz
HDD: Seagate 1TB + Hitachi Deskstar 500gb
Memory: 2 x 1024MB PC2-5400
Motherboard: Asus M2A-VM
Video Card: ATI Radeon HD 2600 Pro
Video Card Driver: ATI Catalyst 2007.0613.1506.25058
Sound Card: RealTek HD Audio
Sound Card AC3: no AC3
Sound Card Driver: 5.10.0.5404
1. TV Card: Hauppauge HVR-1800
1. TV Card Type: ATSC/Analog Hybrid
1. TV Card Driver: 1.25.25271.0
2. TV Card:
2. TV Card Type:
2. TV Card Driver:
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec: Cyberlink
MPEG2 Audio Codec:
h.264 Video Codec: CoreAVC
Satelite/CableTV Provider: none
HTPC Case:
Cooling: 2 x 120mm fans, silverstone clim cpu fan
Power Supply: 450W
Remote: MCE Remote
TV: LG W2242TQ-BF Monitor
TV - HTPC Connection: DVI

When I try and play DVDs, it goes to a black screen and nothing happens - no sound, no menus.
If I try and play the DVD in media player classic it tells me DVD: copy right fail.
I have Cyberlink PowerDVD 8 installed, and the dvds will play fine using their player, but nothing else seems to work. I also have the K-Lite Codec v4.3.4 pack installed.
I've tried changing the dvd codec that mediaportal uses. ffdshow, powerdvd8, gpl mpeg1/2, intervideo,
and none of them work. If anybody has some insight to this problem, it would be greatly appreciated.