I might do a clean install of the whole shebang. I was thinking of switching from 64 to 32 bit anyway. I'll let you know how I get on. Hopefully at the end I'll have some useful info for the Wiki so this doesn't happen to anyone else!
Hmmm... that may well be the problem. I would strongly recommend using the 32bit build anyway... we never use the 64bit ever as it has always caused numerous stability problems. Its possible that your problems are to do with using the 64bit build... they may not be of course but I would the chances are high.