DVD not playing (1 Viewer)

[Peter2]

MediaPortal Version: 0.2.3-17086
MediaPortal Skin: FooTwo
Windows Version: Xp sp2
CPU Type: AMD Athlon 64 X2 4450E
HDD: Samsung 320GB Spinpoint T166 SataII
Memory: Apacer DDR2 PC6400 1024MB Passive
Motherboard: Gigabyte GA-MA78GM-S2H
Video Card: Asus EN8500GT Silent/HTP/256M
Video Card Driver: 6.14.11.6218
Sound Card: Onboard Realtek ALC889A
Sound Card Driver: 5.10.0.5532
1. TV Card: Hauppauge Win/TV PVR 350
1. TV Card Type: Analog
1. TV Card Driver: 1.18.21.22301
2. TV Card: Hauppauge Win/TV PVR 150
2. TV Card Type: Analog
2. TV Card Driver:
MPEG2 Video Codec:
MPEG2 Audio Codec:
h.264 Video Codec:
HTPC Case: Antech Fusion
Cooling: Boxed cpu cooler & 1x120mm case fans (disconnected 2nd 120mm)
Power Supply: Standard
Remote: Hauppauge silver 45 buttons
TV: Sony KV-29FX20B
TV - HTPC Connection: (TV) Scart -> Scart convertor -> S-Video (Integrated TV-out of mobo)

Hi,

For some reason, my system won't play dvd's anymore.
When I start the dvd, the screen goes black and nothing happens. If I push the foward, reverse or pause buttons, the 'progress/time-bar' appears but that's it.

Does anyone have an idea what might be wrong?
TIA
P2