ok Something really strange just happened!!!!! I was trying to get the sound level indicator to work on the front of my case:
http://www.thermaltake.com/product/C...h-d050-2sn.asp
well I followed the cable and it lead to one marked speaker and I had already connected this to the block of switches (you know the ones all on a block on the left hand side of the p5b e.g. power led, power switch, reset switch) but it wasn't working. So I removed the extension block so there was nothing plugged in the mobo as a power switch or reset switch. I trie my old trick of using the nearby fan connector to try and get some power through the cable marked "speaker" well it made a weird kinda click each time I plugged it in and out. Then my computer restarted itself no warning just restarted.....