I spoke too early. In fact the BSODs stopped for about 24 hours, and then were back again, with the interesting difference that, with the hotfix installed, the machine actually stalled on the bluescreen and had to be manually restarted.
Your information that this was a bug in Windows 7, however, saved me from the reinstallation of the OS I was contemplating, which would only have served, at the cost of hours of effort on my part, to have reintroduced the situation I was hoping to escape from.
Instead, I headed over to Softpedia and downloaded a copy of SP1, the installation of which was not as exciting as promised - my computer did not restart many times, only once - but, fingers crossed, they do seem to have nailed the bug. Everything is rock steady.
Excuse me while I go and lie down. Have a nice day.