We recently purchased a refurbished HD PVR which came with a 1056B03 remote. The remote seems to work fine one minute and then won't respond the next. When you push a button the Cable button lights up, but the PVR doesn't respond. I have tried changing the batteries, and we are definitely pointing it at the PVR and are within range. It's not an IR problem as the channels will not change even with the TV turned off. Any ideas?