I am using hibernate 3.2.1-ga version.

I have extended the DB2Dialect and defined my own function:
registerFunction("svminus1", new SQLFunctionTemplate( Hibernate.TIME, "current time") );

It is working fine with ASTQueryTranslatorFactory

HQL: select svminus1() from Temp c where c.id=1
SQL: select current time as col_0_0_ from TEMP c0_ where c0_.ID=1

But when i use ClassicQueryTranslatorFactory, it gives me errors:
HQL: select svminus1() from Temp c where c.id=1
SQL: select svminus1() as col_0_0_ from LIS.TBCONTROL controldat0_ where (controldat0_.CONTROLID=1000001221 )

COM.ibm.db2.jdbc.DB2Exception: [IBM][CLI Driver][DB2/NT] SQL0440N No authorized routine named "SVMINUS1" of type "FUNCTION"
having compatible arguments was found. SQLSTATE=42884

Why am i getting this error?
Also when converting HQL to SQL, it hasn;t replaced my custom function with it's definition.