I did a fresh install of Ubuntu 12.10 today and now am getting the following error: You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies: firefox-globalmenu : Depends: firefox (= 17.0.1+build1-0ubuntu0.12.10.1) but 16.0.1+build1-0ubuntu1 is installed E: Unmet dependencies. Try using -f. When I run the sudo apt-get -f install...I get the following after I type the "y": (Reading database ... 179765 files and directories currently installed.) Preparing to replace firefox 16.0.1+build1-0ubuntu1 (using .../firefox_17.0.1+build1-0ubuntu0.12.10.1_i386.deb) ... Unpacking replacement firefox ... dpkg-deb (subprocess): decompressing archive member: internal gzip read error: '<fd:4>: incorrect data check' dpkg-deb: error: subprocess <decompress> returned error exit status 2 dpkg: error processing /var/cache/apt/archives/firefox_17.0.1+build1-0ubuntu0.12.10.1_i386.deb (--unpack): cannot copy extracted data for './etc/apparmor.d/usr.bin.firefox' to '/etc/apparmor.d/usr.bin.firefox.dpkg-new': unexpected end of file or stream Please restart all running instances of firefox, or you will experience problems. Processing triggers for bamfdaemon ... Rebuilding /usr/share/applications/bamf.index... Processing triggers for desktop-file-utils ... Processing triggers for gnome-menus ... Processing triggers for man-db ... Errors were encountered while processing: /var/cache/apt/archives/firefox_17.0.1+build1-0ubuntu0.12.10.1_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1) This error is preventing me from installing Synaptic package manager and is also preventing me from installing anything with the Software center or Update manager. I tried uninstalling Firefox and also upgrading Firefox to no avail as well. Open to suggestions.