data relationships out-of-sync & duplicate entry

We are experiencing some serious issues with Flexifield. We are at the point where we have to decide to continue using this module by either debugging the problem or moving to nodereference and redoing a big chunk of the website we just finished.

Scenario:
Everything seemed to work fine for almost a year until data became out-of-sync. Flexifield records all of a sudden started to appear on different nodes. We also noticed that MySQL was throwing the following errors during node saves:

"user warning: Duplicate entry '6107' for key 1 query: INSERT INTO flexifield_items (item_id) VALUES (6107) in ###/includes/common.inc on line 3528.
user warning: Duplicate entry '6108' for key 1 query: INSERT INTO flexifield_items (item_id) VALUES (6108) in ###/includes/common.inc on line 3528."

Flexifield seems to become very unstable when data corruption appears. We use it in conjunction with other modules (filefield, imagefield). We need a fail-safe in the module that will prevent data loss or data being linked to different nodes during a wrongful save or a browser crash during a save. We make intense use of the Flexifield which could also contribute to this problem.

We hope somebody experienced something similar and has a solution to the problem.