Not sure if you fixed your problem, but it sounds like a port problem. Obviously, if you fixed the problem you can ignore me
If not.. next time you're at work, go to
http://www.seemyport.com . This site will let you see if the ports are opened on your network. You can also use
http://www.utorrent.com/testport?port=XXXX , just change XXXX with the port number. These sites will let you know if the port isn't open, but just because they are not opened does not mean they are blocked. A lot of that depends on the firewall/router settings on the server whether they only allow connections from allowed ports.
WoW uses 1119 TCP and 3724 TCP for gameplay, 3724 UDP for in-game voice chat, and 6112 TCP 6881-6999 TCP for blizzard downloader. Check those ports.. you'll know whether or not thats the issue.