We have a SharePoint 2007 in our environment and our users are reporting that they will make changes to excel files and will go back the next day and the changes will be gone. This happens randomly but it is happening to multiple people in different sites. Does anyone have any insight into the issue?
This was happening to me with Word documents. It seems to have been fixed for me by changing the "Save Checked-out Files to:" dialog in the office menu from "the server drafts location on this computer" to "The web server".
YMMV, of course, as this is a broad problem that could have more than one issue underlying it. If this doesn't fix anything for you, please update your question with more details.