I have an add-in that uses:

Set MenuObject = Application.CommandBars(1). _
Controls.Add(Type:=msoControlPopup, _
Befo=PositionOrMacro, _
Temporary:=True)
MenuObject.Caption = Caption

to create a new menu item. It works fine on 98% of our supposedly
identical machines but on the other 2% it will not run. I've seen
"Detect and Repair" occasionally fix the problem but not on all
machines. Anyone know what's going on and how to fix it?