A query like this:
SELECT department, avg(salary) FROM Employee GROUP BY department HAVING avg(salary) > 6

evaluates to this SQL:
SELECT `A0`.`DEPARTMENT`,AVG(`A0`.`SALARY`) FROM `EMPLOYEE` `A0` GROUP BY `A0`.`DEPARTMENT` HAVING ((SELECT AVG(`A0`.`SALARY`) FROM `EMPLOYEE` `A0`) > 6)

when it should evaluate to something like:
SELECT `A0`.`DEPARTMENT`,AVG(`A0`.`SALARY`) FROM `EMPLOYEE` `A0` GROUP BY `A0`.`DEPARTMENT` HAVING AVG(`A0`.`SALARY`) > 6;

Please see the thread for more details.