Checkbox won't delete

[foxguy]

I'm using this code to delete all checkboxes below a given top.

 
               With sh
                    For i = 1 To .CheckBoxes.Count
                        Set ck = Nothing
                        On Error Resume Next
                        Set ck = .CheckBoxes(i)
                        On Error GoTo HE
                        If Not ck Is Nothing Then
                            If ck.Top >= dTop Then
                                ck.Delete
                            End If
                        End If
                    Next i
                End With

No matter what I do, it always leaves one checkbox. It deletes all the others, but always leaves one.