Am trying to add objects with the same Ids to a collection of type ICollection, and this collection is mapped in another domian object as a Bag; now what's going on is sometimes the added objects with the same Ids are ignored and sometimes they are added???

here is a part of my mapping files:

<bag name="EmployeeBenefits" inverse="true" cascade="all-delete-orphan">
<!--one-to-many association.-->
<key column="RawTransactionID"/>
<one-to-many class="EmployeeBenefit" />
</bag>