There are things you can do from within access, but it depends on the nature of your application. Are you the only user, or are there multiple users for instance?
In some cases it could be as simple as having a procedure that creates a copy of the database when the user logs on.
Another option could be to use a system like KeepIt.Com for taking online backup.
I would not recommend DropBox for taking backup. If you have your db located in a dropbox synchronized folder it can severely affect performance and increase the risk of corruption.
If corruption is the main cause of your data loss, I can add that I used to experience a fair share of database corruption in Ac2003, but after following these simple steps I have had no corruption since then:
- Never edit running code. If your in debug mode, its fine to see where the error is occuring, but after you've viewed the location, kill the process.
- Do your edits, then Compile.
- Only run compiled code.