Hour MySky decoder has gone on the fritz - at least once if not more times a day the UI freezes up but with the live TV continuing to play in the background. If there's a banner on-screen you can't remove it and if you are in the Planner or Guide it is frozen. Sometimes after a long delay it catches up on all the keypresses like a type-ahead buffer. Sometimes it needs a reset and sometimes it needs a power cycle. The HDD diagnostic does give an error code.
Finally got round to calling Sky this afternoon. They said "there is a technician in your neighbourhood, he will be there shortly and that he'll probably just swap the decoder (with loss of recordings unfortunately) The person on the phone seemed to understand that I knew what I was doing and didn't insist on asking me a lot of newbie questions off a sheet.
Pretty good service.