queries on joins


We have some problems using the predefined joins.

Here is an example of one our query on a join (using key):
In this query we try to gather information about the projects (PROJET) a person (PERSONNE) is assigned to, using the person’s name (NOM) as a parameter and asking the project’s subject (SUJET_PROJET) as a response:


Where TUTEUR is the name of the join Doctype, IDREF_PERS(join to the doctype PERSONNE using the attribute NO_PERS) and IDREF_PROJ (join to the doctype PROJET using the attribute NO_PROJ) are the objects in the schema that represent the joins (we can send you the schema files if necessary).

We have some problems when we make this kind of query on our predefined joins, the result is sometimes quite unexpected like:
1- Data that is not associated with the key we made the query on (random data) is returned
2- Only one result (of many) is returned when we make a query on a specific join

It seems that, from a join, we cannot go through two doctype trees at the same time. Is it normal?