I switched the box on from standby at about 1130 this morning and started watching BBC1 live via the box at 1200. At the start of the news at 1300, the screen went blank and then returned to the programme after a few seconds.
I then noticed that the red light was on, suggesting a recording in progress, but there was none, also I could not control the box from the remote. I then pressed power-on and the red went out and it was working as normal. I have no idea what happened.
Even though it seems to have recovered itself, as soon as I can do a power off/on, I will.
Edit: Note, the blue light on this box is now so dim that I never see the purple mixture any more for "recording", just the red (which also means "Standby").
Edit2: Rebooted and still seems to be running normally. Baffled!!