I'm sure it's all to do with what's held in the cache memory- either of the PC or your server at work.
Just log out of AB, clear the cache, then log back into AB.
Does that work?
With Internet Explorer, go to Tools > Internet Options. The 'General' tab will probably be pre-selected. If not, click on it. Under 'Temporary Internet Files', click 'Delete files'
(Those instructions are for IE6 but later versions are probably similar).
With Firefox, go to Tools > Options. Click on 'Advanced'. Select the 'Network' tab. Under 'Offline storage' click 'Clear now'.
Chris's solution is probably sufficient, but just in case I also delete cookies and history as well. I suggest you also log out of AB first and then log back in afterwords