If you hit ctrl-end (on each worksheet), do you go way past where you know the
data ends?

If yes...

Visit Debra Dalgleish's site for some techniques for resetting that
lastusedcell.
http://www.contextures.com/xlfaqApp.html#Unused

And if you have pictures/objects/comments embedded on those worksheets, they
could be causing trouble.

Eileen Adams wrote:

I have a multi-page Excel spreadsheet. Each page only uses an 8.5 x 11 inch
area, yet the file is 22 megabytes. It takes a long time to open and save.

--

Dave Peterson