I have a spreadsheet where some cells reverted automatically to it previous
values. This is the first time that I have anything close to 130 columns and
8000 rows.

I would change some values, save and make some more changes. Then all of a
sudden when I noticed previously changed data were the same as the original.
I thought I was going insane, but it did happen more than one occasion.

I did worked on the worksheet in both Excel 97 and Excel 2002 before. Any
problems there?

Ming