Error in Hibrenate Firebird DIALECT ?

After:
select r.id, sum(w.CenaSp*z.Ilosc) from ...
error:
Hibernate: select rozliczeni0_.rozliczenie_id as x0_0_,
sum(wzor2_.CenaSp*zamowienie1_.Ilosc) as x1_0_ from Rozliczenie rozliczeni0_
left outer join ZamowieniePozycja zamowienie1_ on
rozliczeni0_.rozliczenie_id=zamowienie1_.zamowieniepozycja_id left outer
join Wzor wzor2_ on zamowienie1_.wzor_id=wzor2_.wzor_id group by�
rozliczeni0_.rozliczenie_id
8912 [main] WARN util.JDBCExceptionReporter� - SQL Error: 0, SQLState: HY002
8912 [main] ERROR util.JDBCExceptionReporter� - Column name x2_0_ not found
in result set.
8912 [main] WARN util.JDBCExceptionReporter� - SQL Error: 0, SQLState: HY002
8912 [main] ERROR util.JDBCExceptionReporter� - Column name x2_0_ not found
in result set.
8922 [main] ERROR util.JDBCExceptionReporter� - Could not execute query
org.firebirdsql.jdbc.FBSQLException: Column name x2_0_ not found in result
set.
������� at org.firebirdsql.jdbc.FBResultSet.findColumn(FBResultSet.java:694)
������� at org.firebirdsql.jdbc.FBResultSet.getField(FBResultSet.java:401)
������� at org.firebirdsql.jdbc.FBResultSet.getInt(FBResultSet.java:457)


select r.id, sum(w.CenaSp+z.Ilosc) from ...
Works fine

�

on HSqlDB both works OK


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