IIQ RAW FILE CORRUPT - PREVIEW

Hi,

I am trying to backup a backup. While copying my past sessions to another disk, OSX Finder stops copying due to apparently a corrupt file, always happens to be a *.IIQ or a *.cos or a *.cop file.
So I opened the session, indeed often the large preview does not want to load correctly. I then deleted the preferences files to recreate new preferences and preview. It works when it is a *.cos file, but when it happens to be due to a bad *.IIQ file or a *.cop file, there is no way I can repair the file/problem. So I end up with an unusable RAW IIQ file and that is problematic.

I also tried :
- creating a new session and importing only IIQ files to see what happens starting from scratch,
- moving, changing, recreating the *.cop / *.cos / *.cof files
- changing the session and IIQ names

MY QUESTION IS : Is there any tool / way to repair a corrupt RAW file ? Any program ?
Has anybody experienced that, and maybe solved their problem ?

Here is what CaptureOne log shows (I added "****" in the file/session names for discretion towards my client, sorry for that, the problem does not come from the file naming) :

Description: Motif inconnu
Fichier: /Volumes/SAUVEGARDE CAPTURES N14 26052011/20111114_****/20111118/****_COMPACT/Capture/CaptureOne/Cache/Proxies/****_COMPACT_028.IIQ.cop
Domaine: com.phaseone.captureone
Code: 1