Inviting Coworker

[Demagogue16]

I've currently joined a workspace and am trying to invite a fellow coworker into the same workspace.

I will invite him, he recieves the invitation and accepts.  Then at the bottom of my Collanos program it says "40.08 MB out" and that number slowly goes down.  On my coworkers computer however, nothing ever changes, we have waited for a few hours and nothing happens.  Eventually his Collanos program logs off and the number at the bottom of my screen shows "1.67 MB out"

Are we doing something wrong?  We're both running the program as adminisrators, I'm on Vista, he's on XP sp2 and we are both running compatibility mode.

Does it matter that I did not create the workspace?  Does he need to be invited by the person who did?  I have manager permission.

Thanks.