Using Derby, we had an intermittent transaction failure with error message “A SAVEPOINT with the passed name already exists in the current transaction”, which appears to be caused internally by Derby.  I see that there are four JIRA issues which relate to this particular error message (DERBY-2773, DERBY-1457, DERBY-2808, DERBY-2804) and which could possibly be related.  I filed a new issue at https://issues.apache.org/jira/browse/DERBY-3093.  Is there any progress on any of these issues?