Either way, I would suggest trying a signal booster. Get one with variable gain. Turn the gain right down, see how it looks, and then gradually increase it until you get the best picture.
Thanks Matt, I've tried an old signal booster that I had and it didn't work but I'm not confident the signal booster is doing it's job.
Could it be that the quickview software is only utilising one tuner?
Unfortunately I can only view and not record with the software and it only allows one window. I did find the config GUI wich is showing 100% for all signal strength, quality and symbol quality for both tuners when on different channels and they stream around 4 to 8 Mbps So I think the network can cope.
When we shipped with MythTV 0.23 we had a load of tuning related problems when using HDHomeRun's (a Myth bug and not a problem with the HDHomeRun)... it seems likely you may be suffering that problem too. MythTV 0.24-fixes corrects this problem and many others too by the way.
What is the best way to go to 0.24-fixes. Can 810 be upgraded and how?
Is it best to go to 1004?