Yeah, I was afraid of that BEFORE spending said time with Comcast. :)

Thanks for providing your reasoning, Michael. I understand that an answer from this site will not fix the problem, but I do want to know HOW to get this problem fixed (or who to push to get it fixed). I don't want to just say "oh well", guess I'll use someone else's Internet till this IP gets dumped on someone else, so they can waste two days with L1 tech support. In any case, thanks.