Odd. As far as I've been told TCP via port 80 should be one of the things that's pretty much guaranteed to work through our firewall, so long as the request goes via regular HTTP or HTTPS at least. It's not using some weird protocol instead of those, is it? Last time we had an application that exhibited anomalous connection problems, it turned out to be that.
EDIT: I just noticed the date on this - I suppose this forum doesn't get the greatest amount of traffic, as it was still on "page 1"! Did you ever get it sorted? Not all of those links work any more, and those that do are clear as mud.
(Suppose I can close the other tabs I popped open with even earlier problem reports in them without even reading 'em, then...)