The problem appeared out of the blue. I've never experienced this, it pretty much fails to bind to any port from 64100 to 64163 according to the console.

Rebooting fixes this usually(once or twice it fails), but I can't reboot every time it fails to do so. Why would this be happening?

I've owned Crysis 2 since like last year April, and this problem appeared just a few days ago.