No Picture In Live TV?

I bought a new computer last week & it's pre-installed with Windows 7. When I first put in my Mini TV DVB-T USB stick, Windows 7 found drivers for it and WMC recognised it and gave me instant TV to watch. However, just this last 2 days it all went sour. I still have the channels listed but on each one I get sound and just a black screen. No idea what changed, perhaps a Windows update as you get heaps of these when running a new system. Anyway I have tried running the USB drivers again and re scanning my channels but the result is still the same. It's so annoying knowing it has worked but now it won"t. Here's my system stats.