After much scratching my head over why the enterprise tests simply do not work despite they already worked in 3.2.3, I realized the job executor was running, which interferes with the enterprise scheduler and message services. The job executor launcher has to be disabled and the commented out ejb and destination references must be uncommented and resolved against the EJBs.

The forum link discusses ear vs sar packaging, which influences how the ejb and destination references will be resolved.