Microsoft Access corruption with linked application to mdb file.

I have a client with an Access application. The system has a front-end linked to a back-end running compatibility mdb files. There are approximately  10 users connected to the application using various versions of Microsoft Office.  The system is experiencing frequent issues which appears to be corruption in the database. When this happens they are receiving  “Disk I/O error trying to read” and sometimes “Unrecognized database format J:\Purchasing\Inventory Control\MICBE_NA_1.0.2.mdb”  error messages. Originally it appeared that these issues occurred when a single table was being read "Item_Master". However yesterday this happened when a user clicked a bound checkbox having now connection to the Item_Master table.  One time the primary key was destroyed in their PurchaseOrders table which we were able to fix after identifying and fixing duplicate key records.

We have continually executed compact&repair procedures and also decompliles.

I know we need to upgrade the back-end to SQL Server but my client is reluctant to do it because they like to connect directly to tables and queries for data entry and maintenance.

If they upgrade to the newer "accdb", is that likely to solve the corruption issue? Are there any procedures we should try to see if we can identify the cause and solution.

Thank you very much!!