Access 97 in a Win2K/Win98 environment

I am a Desktop Analyst supporting a group of 40 users in a mixed Windows 2000 Pro and Windows 98 environment. Both platforms are running MS Office 97. On an almost daily basis, their access database comes up with the following error:
“The database…needs to be repaired or isn’t a database file. You or another user may have unexpectedly quit Microsoft Access while a Microsoft Access database was open. Do you want Microsoft Access to ttempt to repair the database?”