We opened an Excel 2002 file emailed to us in our Excel 2000 program. Ever
since then, we get an "error (9.0.6926SP-3) File Format is not Valid"
message, but allows the workbook to be opened anyway.
Even now when we open a blank (New) workbook file, the same error message
appears, but allows the program to proceed.

How do you get rid of this error nuisance?

James