spinbutton fails every second time?!

[fottet06]

I am currently making a userform but have now for long time received a strange bug. My userform has a listbox with items and 4 assigned spinbuttons which are machines. Items can only be processed on 1 or 2 machines, and they vary. So I want the spinbuttons to be disabled for those machines that cannot handle an item. But when I perform my userform every second it gets a value to the cells, and every second time the cells are blank. I really dont get it why it Works half of the time?!

 

[fottet06]

Private Sub lstItem_Change() If lstItem.Value = "Tiny VVA" Then
optM1.Enabled = False
optM2.Enabled = False
optM3.Enabled = False
optM4.Enabled = True
End If End subRange("B" & r).Value = lstItem.Value
If optM1 = True Then
Range("C" & r).Value = lstTotalTime.Value
End If
If optM2 = True Then
Range("D" & r).Value = lstTotalTime.Value
End If
If optM3 = True Then
Range("E" & r).Value = lstTotalTime.Value
End If
If optM4 = True Then
Range("F" & r).Value = lstTotalTime.Value
End If