I am getting Run-time-error 1004 "ListIndex method of listbox
class failed"

It stops at
ListIndex = RowNo ' Error
using excel 97. It was written in excel 2000 and works fine in 2007. I
was testing it with 97 and it I get this error.
I changed From
.ListIndex = RowNo
to
For .ListIndex = 1
Still fails. Is this one of those commands that did not exist in this
for in 97 version.
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Sub aSlideShow()
Worksheets("Sheet2").Select
With Worksheets("Sheet2").Shapes("List Box 1").OLEFormat.Object
Sheets("Sheet4").Range("AH20").Value = .ListCount
AddressNo = "initial"
'MsgBox .ListCount
For RowNo = 1 To .ListCount

..ListIndex = RowNo ' Error

AddressNo = .List(.ListIndex)
If AddressNo = "" Or AddressNo = " " Then 'Detect blank
.ListIndex = 1
Call ListBoxAuto
Exit Sub
End If
Application.Wait (Now + TimeValue("0:00:01") / 2)
OpenForms = DoEvents
Call ListBoxAuto
'On Error GoTo Finis
Next RowNo
End With
Finis:
End Sub