If you google it this occured to alot of people last Friday. THe common denominator I've seen so far seems to be XP for 1...not Vista...and alot of ppl were using the Free new AVG.
I have bought a new HD and re-installed OS and game ..no A/V and problem still exists, but maybe it was triggered by my old install running AVG.
Either way....there is an issue and it is PB's fault.
V