Moving the bibliography to the main tex document solves the problem with the bibliography and now bibtex exits (with errors, but producing a valid biblio). I didn't commited the fix or removed the Bibliografia.tex file in order to let you decide if this is ok to you.
Comments
The same patch is at muy git repo https://gitorious.org/libro-sig/main/commit/44f9d36d99f2a867110b8ee2c6eb... If it's ok I can also remove the empty file and apply this fix to the svn on my own so you don't have to do anything more.