Toolbar and menu customizations are saved in *.XLB file.
Do a file search for *.XLB and locate where it(they, you may have more than
one).
Note the location(s) and make some changes to a Toolbar or menu then close
Excel and see which *.XLB is updating.
Save a copy of this *.XLB as you make changes. You can then copy it if you
lose it again.
Why are you losing it occassionally?? Are you on a network or stand-alone?
Servers can often screw up with file storage. If the *.XLB gets lost, Excel
just builds a new default one...as you have discovered.
Gord Dibben Excel MVP