I also have this problem when trying to create a topic connection (with username and password) from a windows client to a linux JBoss server through a UIL2ConnectionFactory. The UIL2 client works fine when running on the same linux machine as the server. It also works through the RMIConnectionFactory from the windows machine.
I have exactly the same problem between a Windows 2000 and a Linux RedHat 8. I use JBoss 3.0.2. The UIL2 ConnectionFactory doesn't exist for this version. I'm using RMIConnectionFactory between my JBoss servers and UILConnectionFactory from applet that access the servers.