problems logging in

A strange one here
I can log in to site no bother fom my comp at home but i cant from my office. I said it to IT guy (as i know he looks in here)and he said something about work internet going through a different server. What happens me logging in is that it goes through the motions of logging me in and then bounces me eventhough my name is displayed in logged in users. Can anyone shed some solas on this for me please