Thanks people!
My probs do sound a lot like ZrByte's, you are right!
However, I think, as it hasn't happened before, and there was a thunderstorm, that it is most likely to have been due to that (I hope). If it happens again, I will be off begging for money to buy a tank-sized UPS
The electrics are really dodgy in this house though. A while ago I started getting electrocuted turning on the taps in my bathroom (it used to be a rest home, so we have en suites, lol). My parents thought I was making it up. Turned out there was a plug UNDERNEATH my sink that was still TURNED ON! We had to rip out the sink and so on to find it. The taps had leaked down onto this old plug, which was happily sitting there, big blue sparks flying out of it. No wonder I have such stupid, spiky hair...
I remember ages ago I was running Win 3.11 on a 486, and there was a power cut. Wrecked the entire system. Ah, those were the days...!
P