When I make changes to some Excel files (seems to be the ones larger than 20K) they won't save. I've gone back and forth with WM2003SE the same file changes cause no problems.
I have a mobile excel file that I updated constantly with WM2003SE, and I have updated it with new information several times under WM5, and the changes have saved. The file is more than 100k. I will have to try on other files to see what happens.