If it was read-only, they'd know when they opened it I would think.
You might also have a simple compatibility problem. I go from 2003 to 2000 all
the time, and from 2000 to 97 all the time, but I've not yet tried to go from
2003 to 97. It's quite a back-track and you can feel happy it opens at all. It
may be asking a bit much of it to expect it to save too.
Question (the thread has been chopped off, and I forget) ... is the 97 user
doing "save" or "save as"? There's a slim possibility that "save as" will work
better than attempting to update the existing file.