I have a listbox on my worksheet and have added some items to it
using:

Sub temp()
With Sheets("Month").ListBox1
.AddItem ("Yesterday")
.AddItem ("Today")
.AddItem ("Tomorrow")
End With
End Sub

That works fine but when I close the sheet and open it again the
entries disappear. I can briefly see them and then the list is empty.
I have removed all ThisWorkbook code and I disable macros when the
spreadsheet opens. But the entries still disappear. What's going on?

TIA,
Derek