I had that same problem a while back. Finally figured out it was because the pm software will only allow so many characters to be sent. If I went over that it just froze and I had to close the window from the Task Manager.
I stopped sending back my reply with the original pm I got and problem disappeared. I think the total characters was like 300 or 180, cannot remember the exact number.
If you need it, my email is
dvport4@prtc.net
BTW your email adress is noton your porfile, when clicked on a message pops up saying that you have specified not to receive emails. There is a setting for that in your own profile.