I'm having the same problem, each forum redirects to Cman babes, started this evening (8th March), at first I thought Cman was try to make a buck or two redirecting the members to his site
then I just saw this thread, so it's not just me with the problem, I didn't change any settings or anything on my PC, didn't do any windows updates, AFAIK there's no proxy for me, and my Windows Firewall has been running way before this problem started(just suddenly started tonight).
Norton Internet Security is running with intrusion detection etc, may be it auto updated but still it should not cause this to happen?
also Exp0sed is the ONLY website that's having this problem for me, so it's even weirder.....