Yeah, it happens if only one input is connected. Will try covering the remote receptor and unplugging for a while to see if that helps. Next step will be contacting Denon support, but not looking for much help with that as it's not under warranty.

M60|VP150|2xQS8|PSA XS30+Epik Empire|Pioneer Kuro 6010FD|PS3|Denon AVR-X4000|Parasound 5250v.2|