OK folks, this software is truly DANGEROUS. The command line is incredibly obscure and counter-intuitive, and just trying to SIMPLY restore a single file resulted in duplicity WIPING OUT the entire root file system. What the hell?
I can't say what I typed exactly because as I said the server is gone and the commandlines are friggin complicated and long, however, I pretty damn well remember that I included the "file-to-restore /path/to/blabla.ext" option, and why the FUCK can this result in the software deleting everything? The instruction I gave it is clear: RESTORE A SINGLE DAMN FILE. It was NOT: "ERASE ALL FILES"!
Now if this were paid software I would at least ask for a refund, however, obviously I'll stop using it and warn everyone I'll ever talk to about even considering its use. It's no surprise that mostly everyone I know, even big corporations, still simply make fucking tar archives.