I have isolated that this isn't likely router related as I've followed the steps from this post (great suggestion by the way if there may be a NAT router problem):
http://forums.eqemu.net/viewtopic.php?t=4177
and changed my client's system32/etc/hosts file to point to an internal IP. I get to my character selection screen so it sees the server but then crash on zone loading.
So if I can log onto other people's servers is it safe to assume the problem is likely with my server set up and not with the client?