iscsi target needs to be reformatted ?

[BRJCOMBILENT]

Hi !

I have been using an iscsi target on my TS-459 pro II turbo successfully for over a year now. I use WIN2008R2 to connect to the iscsi target.

But today I was seing some files and folders that appeared to be hidden or duplicated. Trying to delete the duplicated files was not possible. So i tried to disconnect the drive in WIN2008R2, and then reconnect .... but now windows wants to format the drive, and I can not get to the files anymore. The drive appears to be RAW format.
I have tried to connect to the Iscsi target from WIN7, VISTA all giving the same result.
Do you have any tips or tricks on how to resolve this problem ? I really need to get this data restored.

I use a rather old firmware on the NAS 3.4.3 Build 0520, can I risk doing a upgrade ?

Thanks

Brian