Response to: Uh Oh...
Hi FJ, thank you very much for your help.
Unfortunately there's nothing to do.
I've attempt to open the .sparseimage file (35,4Gb!) on other Mac with Disk Utility but it get a -9972 error (missing document in the catalog for extent)!!!
I've also try to repair manually by creating a new account with the same caracters of the original, then compared the start of two .sparseimage files with Disk Editor, but... nothing.
I think that the file is definitively lost.
What do you think?
The last is try to decript the file in the CIA computers!!! :-(