Just a wild guess . . .
Is the program being used in a network environment by multiple users? If so, make sure that nobody leaves the app open on their computer when they leave for the day/weekend/holiday. If the app is open on a work-station when either there is a "less than graceful shut-down" or an attempt to back-up the network, the database can be thoroughly trashed (or, insome instances, it may just have a _little_ garbage dumped in a file or two).
Is someone shutting down or resetting their computer while the app is open? doing the "3-Finger Salute" or hitting the Reet button while the app is open will do the same thing as mentioned above.
In fact, just having multiple users accessing forms that are tied to tables can result in the database being dumped on.
Whenever I develop a multi-user app that has Access as its database, I tend to set it up so that I use something like Delphi as a front end and I force all data entry or modification to be performed in a manner that is somewhat disconnected to the tables. By only doing inserts or updates with a SQL statement, I have found that I have far less corruption occurring.
Ralph D. Wilson II
"Any sufficiently advanced technology is indistinguishable from magic." A.C. Clark