no infection on the PC is going to affect the router - unless you have uPNP turned on, in which case I guess it could hold a port open.
I suspect its more likely that some kind of auto update on the router has made the change or.....theres a small (very very small) chance the router has been hacked.
It being an O2 supplied unit, its presumably preconfigured to your account settings, so simply try resetting it back to defaults. It should simply then revert to how it was
Otherwise, all you can do is what I suggested - ignore the firewall settings and instead "blackhole" the open ports by using the port forwarding capabilities.
PS Steve G tends to deal a lot in hyperbole - after all he has to justify the products he sells from that website somehow. If you've ever spoken to him you'll understand what I mean......most of what he says has an element of truth, he just goes totally OTT with what he says
Last edited by Milo Minderbinder; 3rd January 2013 at 21:54.