file already open error

[Rick]

Hi

Every time I open a saved excel spread sheet I receive this error:

A document with the name 'add-in name' is already open. You cannot open two
documents with the same name, even of the documents are in different
folders."

If I open the file by using the File, Open menu and navigate to the file, I
do not receive the error. It's only when I click on the file which is on the
desktop and open it that way , do I receive the error

There are no other files open at the time. Rebooting does not solve the
problem. WE are running Windows XP SP2 and Excel 97

Thanks in advance
Rick