Hibernate 3.1 and Hibernate 3.0.3

<hibernate-mapping package="com.abc.mypackage">
<class
name="MyClass"
table="parent_table_role"
mutable="true"
>
<cache usage="transactional" region="myregion"/>

<id
name="roleId"
type="integer"
column="role_id"
unsaved-value="any">
<!-- generator class="assigned"/ -->
<generator class="org.hibernate.id.MultipleHiLoPerTableGenerator">
<param name="table">sequences</param>
<param name="primary_key_column">seq_name</param>
<param name="value_column">next_id</param>
<param name="primary_key_value">CM_ROLE</param>
<param name="max_lo">100</param>
</generator>
</id>
<property name="version" column="version" type="integer" not-null="true" length="10"/>
<property
name="roleName"
column="role_name"
type="string"
not-null="false"
length="50"
/>
<property
name="roleDesc"
column="role_desc"
type="string"
not-null="false"
length="255"
/>
<set
name="users"
table="child_table_user_roles"
cascade="all"
>
<key column="user_role_id"/>
<composite-element class="MyRoleDetails">
<property name="approving"
column="approving"
type="integer"
not-null="false"
update="true"
insert="true"
length="10" />
<property name="version" column="version" type="integer" not-null="true" length="10"/>

<property name="userId"
type="integer"
update="true"
insert="true"
column="user_id"
length="20" />

</composite-element>
</set>
</class>
</hibernate-mapping>

for (iter = myRoles.iterator(); iter.hasNext();) {
MyClass aRole = (MyClass)iter.next();

MyClass role = (MyClass)session.load(MyClass.class, aRole.getRoleId());
MyRoleDetails details = new MyRoleDetails();
details.setUserId(userId);

role.getUsers().remove(details);
session.update(role);
}

Hibernate 3.0.3 library generated this SQL :
Hibernate: delete from child_table_user_roles where user_role_id=? and approving=? and version=? and
and user_id=? :


Hibernate 3.1 library generated this SQL :
Hibernate: delete from user_roles where user_role_id=? and version=?


Look at the different SQLs generated by Hibernate libraries (one is 3.0.3 and the other is 3.1).
The difference of the above two SQLs generated is causing me a huge grief.

I like someone to tell me "this is an intended difference or a bug in Hibernate 3.1".

Thanks for your help.