I recently had this happen to me again and I cant find away around it. 

I open WMC and click live tv and this error comes up "there is currently no tv signal detected for this channel"
Ive done a clean install of my Hauppage tv card but that didnt work.  The last time this happened to me it was about a week before I did a Windows 7 reinstall and that obviously fixed it.

Anyone know what I could try?