Unexpectet behavior while using ManyToOne as part ofr composite key

Hi!

Ran into a problem while wanted to use a ManyToOne as part of a primary key:

 * @Entity
 * @Table(name="user_preferences")
  */
class UserPreferences  {

    /**
     * @Id
     * @ManyToOne(targetEntity="User",cascade={"persist"})
     *  @JoinColumn(name="user_id", referencedColumnName="id")
     */
    protected $user;
    /**
     * @Id
     * @GeneratedValue(strategy="NONE")
     * @Column(name="preference_id",type="smallint",nullable=false)
     */
    protected $preference_id;

By default doctrine creates a table with 2 single keys (the preference key is the primary key) which is of course incorrect.
Had to add @Column(name="user_id",type="integer") to the user column to fix the index problem but that introduced another problem. The entity no longer accepter \Entity\User as a value for user and takes only a smallint as defined.