Unexpected behaviour while using notIn

[Alain Becam]

Hello all,
    I have been trying to write a simple query with a notIn:

                        
DBCommand cmdFindPubForPerson = dbPerson.createCommand();
			cmdFindPubForPerson.select(publication4Group.C_PUBLICATION_ID);		 
cmdFindPubForPerson.where(publication4Group.C_GROUP_ID.is(group_Id));
        
DBQuery queryForAssociatedPub = new DBQuery(cmdFindCollForPerson);
                        
        
DBCommand cmdFindPub = dbPerson.createCommand();
        
cmdFindPub.selectDistinct();
cmdFindPub.select(publicationsFromDb.getColumns());	 
cmdFindPub.where(publicationsFromDb.C_ID.notIn(queryForAssociatedColl));

And was expecting this query:

SELECT DISTINCT t11.CREATEDBY, ...
FROM PUBLICATIONS t11
WHERE t11.ID NOT IN ((SELECT DISTINCT t13.PUBLICATION_ID
FROM PUBLICATION4GROUP t13
WHERE t13.GROUP_ID=27))

but got that:

SELECT DISTINCT t11.CREATEDBY, ...
FROM PUBLICATIONS t11, PUBLICATION4GROUP t13
WHERE t11.ID NOT IN ((SELECT DISTINCT t13.PUBLICATION_ID
FROM PUBLICATION4GROUP t13
WHERE t13.GROUP_ID=27))

which is wrong and pretty slow (well should be).

Is there a reason I get the PUBLICATION4GROUP table in the main query 
from? Might be a very stupid question, I wonder if I am not missing 
something pretty simple here :)

//Alain