I'm assuming this is XP, so it could be a Windows Firewall stoping the network at your work from connecting.

Go network connections, Properties of Wireless Network Connection, Advanced Tab, unselect Protect my computer and blah blah blah.

Also if you have any third party Firewalls that you have bought or were pre-installed on your system when you got it.

I can only assume that it is a firewall problem, outside of a faulty device, which doesn't seem likely. Of course if you haven't got XP, post your operating system and sp, you may have to configure it manually.