UF Listbox Problem beim Ändern

Private Sub UserForm_Initialize()
With Sheets("Buchen")
With ListBox1
.Clear
.ColumnCount = 6
.ColumnWidths = "3,0 cm;4,5 cm;4,5 cm;3,0 cm;3,0 cm;3,0 cm"
ListBox1.RowSource = "Buchen!B9:G" & .Cells(Rows.Count, 2).End(xlUp).Row
End With
End With
With Sheets("Hilfstabelle")
ComboBox1.RowSource = "Hilfstabelle!B2:B" & .Cells(Rows.Count, 2).End(xlUp).Row
End With
End Sub

Private Sub ListBox1_Click()
'klick = ListBox1.ListIndex
With ListBox1
UF_Buchungen.TextBox1 = .List(.ListIndex, 0)
UF_Buchungen.TextBox2 = .List(.ListIndex, 1)
UF_Buchungen.ComboBox1 = .List(.ListIndex, 2)
UF_Buchungen.TextBox4 = .List(.ListIndex, 3)
UF_Buchungen.TextBox5 = .List(.ListIndex, 4)
End With
End Sub

Private Sub CommandButton1_Click()
With Worksheets("Buchen")
.Cells(.Cells(Rows.Count, 2).End(xlUp).Row + 1, 2) = Format(TextBox1.Value, "dd.mm.yyyy")
.Cells(.Cells(Rows.Count, 3).End(xlUp).Row + 1, 3) = TextBox2.Value
.Cells(.Cells(Rows.Count, 4).End(xlUp).Row + 1, 4) = ComboBox1.Value
.Cells(.Cells(Rows.Count, 5).End(xlUp).Row + 1, 5) = CDbl(TextBox4)
.Cells(.Cells(Rows.Count, 6).End(xlUp).Row + 1, 6) = CDbl(TextBox5)
.Cells(.Cells(Rows.Count, 7).End(xlUp).Row + 1, 7).FormulaR1C1 = "=SUM(R[-1]C[0]+R[0]C[-2]-R[0] _
C[-1])"
End With
''zeigt Bestand in Textbox6 an
'TextBox6.Value = Cells(Zeile6 + 1, 7)
End Sub

Private Sub CommandButton4_Click()
Dim lastRow As Long
lastRow = Range("B65536").End(xlUp).Row
With Range("Buchen!B9:G" & lastRow)
Me.Tag = "1"
.Cells(ListBox1.ListIndex + 1, 1).Value = TextBox1.Value
.Cells(ListBox1.ListIndex + 1, 2).Value = TextBox2.Value
.Cells(ListBox1.ListIndex + 1, 3).Value = ComboBox1.Value
.Cells(ListBox1.ListIndex + 1, 4).Value = CDbl(TextBox4)
.Cells(ListBox1.ListIndex + 1, 5).Value = CDbl(TextBox5)
Me.Tag = ""
End With
UserForm_Initialize
End Sub