Well if NONE of the options in that thread helped i couldnt tell you what the problem might be.
I have been helping a guy on the network i go to with a similar issue and neither of us can figure out what is wrong. Nothing on his machine is any different than it was before the problem started, no new isp, router, nic, os..... nothing.
I'll keep looking back to see what you get out of this, maybe its a bug (doubtful) or malicious code.