I´m not familiar with it, but maybe WMC is bloking the card.
By the Way, which version are you using?
Hello again
Is this the answer to my question?Yes, ...
If so, you are encountering a known issue with the EPG grabber prevening tuners from being used. I'm calling it TsWriter deadlock. You will need to restart your machine and disable the idle EPG grabber (in the DVB EPG section of TV Server configuration) in order for the tuner to start working again in MP.
[Edit: to be clear, there is nothing wrong with your tuner - this is a TV Server bug]
mm