Hi Rawi, I do not understand EAP and messaging, but I have big experince in the runtime environments.
This look like a bug:
0) you are using JBoss in cluster, messaging and Oracle. It is already a bit complicated environment.
1) You need to do it easier.
a] Try to look for some patches.
b] Try to use it somewhere in the test environment, only for messaging without cluster
if there is no error more, it is clear.
c] if there is still an error, try to check, if there is any problem with firewall.
d] then try to do it without oracle.
e] and so on.
Aim: it looks like a bug. So, you need what is wrong. I hope the configuration you have OK.
Could you give some more details?