latimers: @ELShah - Well that's what I thought too, but no joy.

In the end I bit the bullet (after Wimbledon was over) and sent it down to Hamilton. (They returned it pretty quickly.) A full bench test did not reveal any problems with the HDD or with the rest of the machine. They replaced the HDD just in case it was an intermittent fault. They also suggested adding a UHF bandpass filter to make sure that there weren't any extraneous signals getting through (e.g. from a nearby cell tower).

So far I haven't had any problems, but it's only been a couple of weeks. Time will tell, I guess.

One random thought I had was to wonder whether the freezing was due to the software having problems when the disk was full. After I watch a recording I delete it and it goes in the Trash. (I really like that feature.) In theory when the disk is full of stuff in the trash, it deletes the oldest stuff to make room. Perhaps that process doesn't work correctly but it will cause problems only after a long period of time then the Trash has had a chance to fill up. I started thinking about that because my son had a cell phone a while ago that was supposed to delete the oldest messages when the Inbox filled up. His phone started doing funny things but only after a long period of time after the repair people had had a go at it. We finally traced the cause of the fault but the phone manufacturer never did anything about it.