A user setup an excel spreadsheet to use as a template in Excel XP (2002).
This file is opened successfully from a network drive from both Excel 2003
and 2002.. The user makes changes to this file and then saves it as a
different name to a network drive. When an Excel 2002 user makes changes to
this file and then saves it and an Excel 2003 user goes to open that file
they get:

"File Error: Data May Have Been Lost"

They click OK and get that message about 25 times before they can open the
file. When they do open the file there is indeed a bunch of data missing.

Is there some sort of incompatibility between Excel 2002 and 2003?

2002 to 2002 users do not have this problem.

Thanks for any input.