[mythtv-users] Able to scan and lock channels on backend, 0% signal strength on frontend

[Rob Young]

I've installed Myth 0.21 on Ubuntu 8.04. I run the backend setup, and the tuner setup is able to scan and lock all the local stations I would expect. Once I exit, and run the frontend, I see one perfect frame (picture is not "pixelized" or any apparent digital breakup) for any station I tune, then display freezes on that picture. The channel banner shows 0% signal strength. My setup:

Gigabyte GA-MA78GM-S2H 
Onboard AMD 780g RADEON 3200hd video (proprietary driver installed)
AMD Athlon64 X2 4800+
4 GB RAM
1 TB WD SATA HD
Ubuntu 8.04 (Hardy)
Happaugue HVR-1250 ATSC tuner

In all my "google"ing, I only found one possible solution that someone mentioned pertaining to the editing the channel transport polarity being set to H or V. When I look at my channels via the transport editor, since my set up is broadcast and not satellite, I see no transport polarity setting, only the channel frequency. Any suggestions on where to start troubleshooting this? 
thanks,

Rc