I don't know why it doesn't stick for you, but you could do something like...
Create a workbook with this code in a general module:
Option Explicit
Sub auto_open()
On Error Resume Next
Workbooks("autosave.xla").Excel4IntlMacroSheets("Loc Table") _
.Range("ud01n.Frequency1").Value = 1
If Err.Number <> 0 Then
MsgBox "Timer not changed!"
Err.Clear
End If
On Error GoTo 0
ThisWorkbook.Close SaveChanges:=False
End Sub
Save it into your XLStart folder (so it loads, runs, and closes each time you
start excel).
If you're new to macros:
Debra Dalgleish has some notes how to implement macros here:
http://www.contextures.com/xlvba01.html
David McRitchie has an intro to macros:
http://www.mvps.org/dmcritchie/excel/getstarted.htm
Ron de Bruin's intro to macros:
http://www.rondebruin.nl/code.htm
(General, Regular and Standard modules all describe the same thing.)
Another option would be to dump autosave and use Jan Karel Pieterse's addin
(works in any version) called AutoSafe (note spelling).
It doesn't overwrite the existing workbook when it saves. It saves to a user
selectable folder. And when it's done, it either deletes these backups (or puts
them in the recycle bin). And the user can always restore the backups from the
recycle bin.
http://www.jkp-ads.com/Download.htm
(look for AutoSafe.zip, not autosafeVBE.zip, for your purposes.)