Have you tried Microsoft's JetCompact utility? It can fix most things. Just make sure you properly select whether it's a Jet 3.x or 4.x database.

If that doesn't work, I can get you a 3rd party tool or fix it for you.

I'm assuming the front-end application is an Access MDE file...If so, do you know how it links its tables? You may be able to put your data in a mysql database and link it manually and use that instead.

(file hosted on my server...not sure where to get it officially)