Comboclick no funciona

Tengo 2 combocliks en un userform que llevan el item seleccionado a un textbox.
Uno de ellos funciona perfecto, pero el 2do, no se que le pasa...
Este es el codigo:
'PARA ELEGIR EL CUATRIMESTRE
Private Sub ComboBox1_Click()
Dim i As Integer
Dim final As Integer
    For i = 1 To 1000
        If Hoja4.Cells(i, 2) = "" Then
            final = i - 1
            Exit For
        End If
    Next
    For i = 1 To final
        If ComboBox1 = Hoja4.Cells(i, 2) Then
            TextBox1 = Hoja4.Cells(i, 2)
            Exit For
        End If
    Next
End Sub

Private Sub ComboBox1_Enter()
Dim i As Integer
Dim j As Integer
Dim h As Integer
Dim final As Integer
Dim tareas As String
ComboBox1.BackColor = &H80000005
    For i = 1 To ComboBox1.ListCount
        ComboBox1.RemoveItem 0
    Next
    For j = 1 To 1000
        If Hoja4.Cells(j, 2) = "" Then
            final = j - 1
            Exit For
        End If
    Next
    For h = 1 To final
        tareas = Hoja4.Cells(h, 2)
        ComboBox1.AddItem (tareas)
   Next

End Sub

Private Sub ComboBox2_Enter()
Dim a As Integer
Dim b As Integer
Dim c As Integer
Dim final2 As Integer
Dim tareas2 As String
ComboBox2.BackColor = &H80000005
    For a = 1 To ComboBox2.ListCount
        ComboBox2.RemoveItem 0
    Next
    For b = 1 To 1000
        If Hoja4.Cells(b, 3) = "" Then
            final2 = b - 1
            Exit For
        End If
    Next
    For c = 1 To final2
        tareas2 = Hoja4.Cells(c, 3)
        ComboBox2.AddItem (tareas2)
    Next
End Sub
'HASTA AQUI FUNCIONA....

'ESTA PARTE YA NO ME FUNCIONA....

'PARA ELEGIR EL AÑO
Private Sub ComboBox2_Click()
Dim a As Integer
Dim final2 As Integer
    For a = 1 To 1000
        If Hoja4.Cells(a, 3) = "" Then
            final2 = a - 1
            Exit For
        End If
    Next
    For a = 1 To final2
        If ComboBox2 = Hoja4.Cells(a, 3) Then
            TextBox2 = Hoja4.Cells(a, 3)
            Exit For
        End If
    Next
End Sub
PD: le envié por email el archivo con el ejemplo
Desde ya gracias por la ayuda...