Using Excel 2003, when we create a new spreadsheet, if we specify the
hyperlink base, it is not saved when the files is closed.
However, we have some files that do save the hyperlink base. They might
have been saved with another version of Excel, I don't know. If these files
are copied or saved-as, the copies also work. On the files that work, the
hyperlink base can be deleted, and later re-created, and they continue to
work.