My understanding is that Messaging 1.4.3 is for AS 5.x only. You should instead download Messaging 1.4.4 and use the util/release-admin.xml Ant script to integrate it with AS 4.2.0
I was following the documentation from
and in the manual installation section it has the following note ---
JBoss Messaging 1.4.3.GA requires specific versions of jboss-remoting.jar if used outside of JBoss 5. If you are installing JBoss Messaging 1.4.3.GA at JBoss 4.2+, you should use this version: Remoting 2.5.0.SP2. If you are using JBoss5 you don't need to take any extra steps on the remoting installation.
Doesn't this mean that i can use JBM 1.4.3 with JBoss 4.2.0 ??
It looks like something is wrong, i would use jboss 5.1 it comes shipped with JBM.