Vexingly, my computer is acting up again. Starting up when I have not started it; closing down when I have not closed it. I am waiting for my computer tech to ring me - presumably we should have installed a new internal power supply last week and the floppy cable was symptom not cause...(I tried disconnecting it at the mains and it started up without my even touching it the moment I plugged back in.) Also, this might explain why G-mail takes so long to open letters and why all browsers crash with buffer overrun messages when I try to log-in to Myspace.
Alternatively, demonic possession which is not covered by virus checkers or spyware checkers.