I would expect that actually saving  it with 97 would get rid of the error.
Are you saying that you get the error when you save with 97, close, load
into 97, save with 97 again? That would be unusual and I've never seen it
(and I do make changes in 2003 then subsequently re-save in 97).

Also, just check that 97's not trying to save as a csv file.

You are correct that copying code from one sheet to another needs to be done
one module at a time. However, just open both sheets and drag the code
modules across to the second sheet in the VB environment. It will assume
"copy" and you only need to drop somewhere on the second sheet's tree view,
so it only takes about 2 seconds each module.