Following on from this I've had a couple of incidents now where I've closed the lid on my laptop ( which is set to Sleep when I close the lid ).

I've then dropped it into my bag only to find ( say ) 20 minutes later that there's a lot of heat coming from the bag ( to be fair, the bag is padded and things warm up nicely in there ).

I pull the laptop from the bag to find that it hasn't actually gone to sleep at all, it's sitting in there gradually melting until ( I guess ) the CPU will finally shut itself down due to overheating.

I didn't use to have this on XP although I didn't used to run this particular laptop with XP so it's not perhaps a fair comparison - I guess I need to get Vista Sp1 and every driver and BIOS update and see if that improves the situation ( or maybe get another laptop ).