I feared that would be the answer.. There have been ongoing issues affecting those who receive or can receive transmissions from Hannington and nearby transmitters for a long time.
If you have the time maybe check this and the Youview community forums for Hannington threads.
I also pick up my signal from Hannington, in fact I live around 2 miles or so from the transmitter, and this problem has been plaguing me for over a year now. I get it with the new (G4) box but didnt with the older box.
It comes and goes...it has happening for the last couple of weeks....if you leave the channel tuned in to the blank screen it often reappears after a minute, or if you tune away then back again it may show up. If you retune you are doomed and will lose the channels until the problem goes away and you retune.
Sorry to be no help...I dont know what the answer to this is....
Yep - Hannington is my local transmitter too - perhaps this is the common denominator............
It seemed to get worse recently. I just turned the box onto BBC4 HD (its the COM7 channels that are affected) and got the blank screen. I pressed cancel and just left it and after a couple of minutes the channel tuned in.