This is most likely due to the overwhelming demand on Microsoft's server'r right now.. I'd keep trying as the demand will subside after a few million people have gotten the RC downloads.. I could be wrong of course but that's most likely the case... unless it's something to do with the college proxy server but I don't think that's the problem as you said your updates are running smoothly..
i also get an error when i try to activate RC1 with my beta key that i got when i downloaded windows 7 from the microsoft website, first day i activated, it worked and said windows is genuine, then after the restart next day i got a message that i need to activate windows in 30 days :| so i tried to activate it again but i got this error:
if anyone else got this working, please help, i had the same problem with the beta release 7077, i am using a broadband connection to the internet, i'm not behind any proxy and i tried it without firewall but still got nothing