This is the problem: after typing the password and entering correctly it crashes. I can't take a screenshot (I think the os didn't recognized the keyboard entirely -it's a laptop-), but the message log is:
"An error occurred
The following details are provided:
E: dpkg was interrupted, you must manually run 'dpkg -configure -a' to correct the problem.
E:_cache->open()failed, please report."
The thing is that when I manually type the command I get this:
dpkg: error: unknown option -o Type dpkg --help for help about installing and deinstalling packages [*]; Use `dselect' or `aptitude' for user-friendly package management; Type dpkg -Dhelp for a list of dpkg debug flag values; Type dpkg --force-help for a list of forcing options; Type dpkg-deb --help for help about manipulating *.deb files; Options marked [*] produce a lot of output - pipe it through `less' or `more' ! I'm running on Lubuntu 12.10
Thanks in advance!