Toolbar and menu customozations are saved in a file named Excelxx.XLB where xx
is your version of Excel.
Usually will be located at......................
C:\Documents and Settings\username\Application Data\Microsoft\Excel
Maybe you don't have permission to save to that folder or the folder in which is
may be stored if not that one.
Have a look for *.xlb file using Windows file search.
See where it is and note the size and date.
Make some changes in Excel to a Toolbar, close Excel and see what happens to
your *.xlb file.
Gord Dibben MS Excel MVP