Check out these threads about "document not saved" on google.
http://snipurl.com/d7fr
You may find out the source of the problem.
Gord Dibben Excel MVP
On Mon, 20 Oct 2008 07:34:06 -0700 (PDT), dkc wrote:
I have a fairly large (4mb) excel file that many people in my company
use. Lately, most of the users are unable to save their changes. The
message is simply "Document Not Saved".
Any help is most appreciated!!