6205 signal loss

[Huw]

I have a tbs6205 on a win 7 64 machine using WMC. Initially reception was fine, then after a while signal started to break up on some channels, now I'm told there is no signal on my HD channels. Configured another PC as a wmc machine with this card, same thing happens. Fed my tv off the same signal, no problems at all with incoming feed.
Drivers are as on the supplied cd.
Any clues?

Huw