Hmm, this is a bit of a standard answer in these cases, but make sure you have cookies enabled and try to clear your cache. That usually does the trick with these things. Also try to disable any pop-up blockers and spyware killers. I wouldn't be surprised if those also block some legit stuff.
If something is wrong with the Banner Exchange and/or helpdesk, i'm sure Thomas will investigate and let us know within a day.