Mango SQL CE: DeleteRule = "Cascade" not working

I am trying to set up an FK relationship between two columns that will remove all children in the Db when the parent row is removed. My definitions look like this:

    [Table]
    public class Parent
    {
        [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
        public int Id { get; set; }

        [Column]
        public string Dummy 
        {
            get { return "dummy"; }
            set { } 
        }

        private EntitySet<Child> _children;

        [Association(Name = "FK_Parent_Child", DeleteRule = "CASCADE", OtherKey = "ParentId", ThisKey="Id", Storage="_children")]
        public EntitySet<Child> Children 
        { 
            get 
            { 
                return _children; 
            } 
            set 
            {
                _children.Assign(value);
            } 
        }

        public Parent()
        {
            _children = new EntitySet<Child>(
                item => item.Parent = this,
                item => item.Parent = null);
        }
    }

    [Table]
public class Child
{
    [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
    public int Id { get; set; }

    [Column]
    public int? ParentId { get; set; }

    private EntityRef<Parent> _parent;
    [Association(Name="FK_Child_Parent", ThisKey = "ParentId", Storage = "_parent", OtherKey = "Id", IsForeignKey = true, DeleteRule="CASCADE")]
    public Parent Parent
    {
        get
        {
            return _parent.Entity;
        }
        set
        {
            var previousValue = _parent.Entity;
            if (previousValue != value || !this._parent.HasLoadedOrAssignedValue)
            {
                if (previousValue != null)
                    _parent.Entity = null;

                _parent.Entity = value;
                if (value != null)
                    ParentId = value.Id;
                else
                    ParentId = null;
            }
        }
    }

}

      

        
        
        
      

    

From what I can tell, it looks like the FK implementation seems to work. Adding a parent row to Db will automatically add child rows; selecting the parent row correctly populates the Children property of all children.

I would also like to be able to delete the parent row in the database and delete it, also delete all associated children. With this setup, when I remove the parent, I get the error "The primary key value could not be removed because references to that key still exist. [Foreign constraint name name = FK_Child_Parent]".

It looks like DeleteRule = "Cascade" is not being enforced, but I'm not sure why.