Have tried turning off Windows Defender, Real Time checking and excluding “C:\Program Files (x86)\bitcoin” but this made no difference.
As another recent thread indicates their problem was fixed or potential solution in this way.
This thread below is the closest match. I can say the crash started the moment I rebooted after October 2010 patch Tuesday, windows update (which were only applied a few days ago).
http://bitcointalk.org/index.php?topic=991.0
FYI - I was not overclocking or otherwise buggering about with anything in ways I’m not meant to. Which the above thread OP claims to have done. Also My Wallet.dat looks fine, none of the AppRoaming files have been modified since I rebooted after installing the 23 updates all in one go.