Posting here so others don't have to waste as much time. My situation: installed router/modem at new place and hooked up to comcast extreme 105. Installed comcast bloatware to get past captive network. Then, went away for holidays.
At new holiday location, with a new connection that wasn't comcast (verizon) virtual server I was running would redirect me, using chrome, to activate comcast services page. To fix, I had to change the DNS setting, to openDNS in my virtual machine (flavor of Fedora Linux). To change, follow the instructions here: http://www.cyberciti.biz/faq/howto-linux-bsd-unix-set-dns-nameserver/
I've been a comcast customer for 5 days, and so far every experience with them has been painful and a waste of time.