IIRC the app simulates several client calling the entity in parallel using version consistency (check sun-ejb-jar.xml). Version consistency is implemented by caching data between transactions to avoid reload (ejbLoad call) on every transaction. If 2 or more threads try to update the same CMP, one succeeds, but all others fail because by their commit time, the version value in the database doesn't match the value that is in the CMP.
The app has been written to retry such failed calls. So when you run the app without any changes, the exceptions are there in the log, but the app itself succeeds.
HTH,
-marina
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