I have a Panasonic DVD recorder with Freeview+ tuner. Model is DMR - EX 769. I switch everything off every night.
When I switch on again after a few minutes this machine presents a message of the form saying that another channel has been detected - do you wish to retune? It does this every time.
I know this is not correct and there are no other channels.
Do a complete new scan .. with antenna disconnected. When it finds nothing, reconnect and scan again/store channels.
Any changes after that are due to broadcast signal strength or your antenna. Try a scan late at night. See how it goes.
If you go into the set-up menu you have the option of turning the "new channel detected" message off.
I've got 2 Panasonic TV's with built in Freeview and it is annoying to keep getting this message.
Do you turn the tuner off at the plug or just put it into standby? I know my freeview tuner updates overnight (TV Guide etc). So I suppose if it is switched off at the plug then it can't update.