Footnotes in WORD 2000

WORD 2000 has suddenly stopped inserting numbers as footnote refernce marks. Instead it inserts what appears to be either an "underline" or a single apostrophe character in superscript. If you try to overtype this with a number, it deletes the footnote reference mark and the footnote. Existing footnotes are fine; it is only in adding new footnotes to an existing document, or to a new document. I've reinstalled and run Repair. Any other suggestions?

 

Hello and welcome to the BBS. Have you by accident clicked on the "Custom mark" button or on the "Symbol" button, thereby changing the number to an underline or apostrophe?

Also check under "Options" in the Footnote dialog box and see if the "Number format" selection has been changed.