DHCP/IP Problem

I am in college, and on the university network. A few
days ago, I was online when out of the blue, I was signed
off AIM and was not able to go to any web pages (it said
i was offline.) However, my network connection is still
active (I can tell because the icon is still in the
bottom right part of the screen.) When i right-click on
it, and go to "repair", it chugs for a moment, then comes
back with an error regarding the IP Address. I went to
the technology services and they had no idea. The thought
was there was a problem with my DHCP settings, but those
are all correct. So the network connection remains
active, I have a valid IP address, but as far as the
programs go, im not online. Could this be a virus (I have
updated Norton, and it says im virus-free.)

please email me if you have any suggestions.