Recently switched primary key's within my tables from the JPA Sequence generator to "uuid2". Prior to this change, everything worked ok. After this change, database updates fail and report the errors listed below. This issue prohibits me from using the "uuid2" generator.

See the readme.txt file in the attached example.zip file to load the enviornment, compile and reproduce the error with an extremely simple test case.

Jun 21, 2013 9:32:57 AM org.hibernate.engine.jdbc.batch.internal.BatchingBatch performExecution
ERROR: HHH000315: Exception executing batch [Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1]

JUnit generates the following stack trace:
org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:81)
at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:73)
at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.checkRowCounts(BatchingBatch.java:133)
at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.performExecution(BatchingBatch.java:110)
at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.doExecuteBatch(BatchingBatch.java:101)
at org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl.execute(AbstractBatchImpl.java:149)
at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.executeBatch(JdbcCoordinatorImpl.java:198)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:372)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:287)
at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:339)
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:52)
at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1234)
at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:404)
at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.beforeTransactionCommit(JdbcTransaction.java:101)
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:175)
at example.db.HibernateEngine.commitTransaction(HibernateEngine.java:40)
at example.db.DB.commitTransaction(DB.java:25)
at tests.TestUpdate.test(TestUpdate.java:23)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)