Hi Jan,
I had the exact same problem with my machine last week. I found that the below fixed it:
Firstly, switch off the unit at the rocker switch at the back. Then remove the aerial from the PVR and then power it on.
Because you have the aerial disconnected, you will now be able to access your menu.
Access your MENU>INSTALLATION>DEFAULT SETTING>YES (your password is '0000' when required)
The unit will now turn itself off and on again.
Once the machine turns off you will need to reconnect the aerial.
This will reset your box and rescan the channels (you will need the aerial reconnected at this point), once this is finished, make sure to SAVE the results, and this should resolve the problem.
Note: It doesn't delete any recorded programmes!
Ad Rogg
November 2009