It would sound as though your work IP is blocked from within the IPB forum software. That would explain why proxies work, and direct connections do not.
When you're at work, try something like www.whatismyipaddress.com, and maybe an admin will be able to see if you've been caught in an IP ban. Remember to ask nicely though, admins are busy people.
' Wrote:Warnings will be issued. Accounts will be banned. In game characters will be deleted. I will drive to your house and punch you in the mouth.