I have had my HDR1000S since November and had no problems, except the known failed recording bug that was fixed in the last software update.
But today, I switch it on at 18:15 and after 10 mins watching live BBC1 HD the box rebooted it self.
Just like someone pressed the standby button and then they switched it back on again (back on BBC1 HD).
So it took the usual long time to boot up again.
After 8 mins I started watching a recording and 2 mins later it rebooted again.
I then put the box in to standby for a few minutes.
Then I did a factory reset.
I have had no problems since.
I have the 500GB hard drive. No network connection and use 2 cable satellite connection.
HDMI to a Sony TV.
I also did a factory reset after the last software update.
I also had a halogen light bulb on at the time and it never flickered or anything. So it can not have been a mains glitch.
Has anyone else any experience of this problem? The only thing I have found is http://community.freesat.co.uk/t5/Products-and-equipment/HDR-1000s-rebooting-for-no-apparent-reason/td-p/3224