Built portal trunk with jdk1.4 and tried to deploy jboss-portal.sar with JBoss AS 4.2.0.GA. Good thing is that I did not see any java versioning issue which I remember seeing earlier. The first error I see is java.lang.NoClassDefFoundError: edu/emory/mathcs/backport/java/util/concurrent/locks/Lock. Thomas had posted some comment about this in forum. Fix is to copy appropriate jar in lib but I am not sure why it's not included in in jboss4.2.0 by default. I think we need to have this in jboss-portal.sar/lib.