Unfortunately, it suffered a number of freezes and crashes. The machine was returned and replaced but the replacement machine was found to have a faulty video and also had to be returned. The freezes were traced to the faulty 1TB HDD by running the Samsung diagnostic program (the original generic diagnostic program had pronounced it okay). Unfortunately, this meant that the original machine was probably okay, but there was nothing that could be done except return the replacement. The 1TB was returned to Samsung under warranty. I also bought a 500 MB HDD as an interim replacement.
This arrived last week and I reassembled the whole machine. Naturally, this coincided with a week in which Gadget was very busy at the office with installing Informatica equipment, and dealing with a power failure. Nonetheless he found time to restore my media centre 500 MB HDD from the backup. For some reason Norton Ghost refused to do it and the disk was restored the old fashioned way, with the dd utility. The 1TB then came back from Samsung and was sold to a work colleague.
The media centre's heat problem was traced to the Bluetooth driver, which constantly consumed 50% of its CPU. This was uninstalled and the power usage dropped down.
Finally, the machine was connected up at home. As before, there was no sound over the HDMI cable, so I substituted analogue sound and VGA. The picture doesn't look as good though.
Nonetheless, the machine now works. I will see how much I use it.