Black screen when starting TV

MediaPortal Version: 1.2.1
MediaPortal Skin: Avalon
Windows Version: Windows 7 Pro SP1
CPU Type: AMD Athlon II 240 X2 2.8 Ghz
HDD: Mushkin Callisto Deluxe 40Gb
Memory: 2Gb DDR2 800 Mhz
Motherboard: Gigabyte GA-MA785GM-US2H
Video Card: AMD Radeon HD 6570
Video Card Driver: ATI Catalyst 11.9
Sound Card: Realtek
Sound Card AC3:
Sound Card Driver:
1. TV Card: Hauppauge TD500
1. TV Card...

Black screen when starting TV