I have comcast as well. I was reading a forum post from a few years ago about dns errors ,and the guy said he fixed it by switching his dns in the configuration manually. He said he set it to something called OpenDNS which was 18.104.22.168 or 22.214.171.124.
I read that before i found out alot of us were having this issue. Once i seen so many of us are having the issue i chose to wait before i tried anything. But if all support on both PS & CS sides are doing is passing the buck it might be worth a try.
My father and i just beat dragons lair together and now we want the second one. We can't download cause its giving me an (ERROR 80710102) So if this doesn't go back up we might as well buy it on the iPhone.