One of the changes in this big patch
http://anoncvs.forge.jboss.com:8080/viewrep/JBoss/jboss-transaction/src/main/org/jboss/tm/TransactionImpl.java?r1=1.64&r2=1.65
causes the transaction semantics to break.

i.e. If a transaction is marked rollback when gets to after beforePrepare()
it just throws an IllegalStateException with no context to the error!!!!

This is wrong. If the transaction cannot be committed it should be rolled back (and tidied up) with RollbackException thrown.
See the jca test that is failing in HEAD
org.jboss.test.jca.test.XATxConnectionUnitTestCase#testBrokenConnectionAndTrackByTx