We've seen incompatibilities between AIX's tar and linux tar.
You might want to try creating a zip/jar of the contents on a windows or linux box and then unjarring it on AIX. (JAVA_HOME/bin/jar -xvf jboss-3.2.5.jar)
I found the problem. There is a difference between the tar that has been used to tar jboss. And the native tar program on aix5.2.
I the one used for taring jboss seems to be gnu version.
I downloaded a gnu version for the aix box and used that which worked!