run the command again but just do as root first: rm -rf /var/lib/dpkg/lock
apt-get -f install system-ui-screenlock-nokia --reinstall
~ # apt-get -f install system-ui-screenlock-nokia --reinstall Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies. meegoal: Depends: python-pyside.qtgui but it is not going to be installed Depends: python-pyside.qtopengl but it is not going to be installed Depends: python-pyside.qtdeclarative but it is not going to be installed Depends: python-pyside.phonon but it is not going to be installed Depends: python-qtmobility.feedback but it is not going to be installed Depends: python but it is not going to be installed mp-harmattan-333-pr: Depends: system-ui-screenlock-nokia (= 1.2.30-1+0m7) but 1.3.3-1+0m8 is to be installed system-ui-screenlock-nokia: Depends: libqt4-dbus (>= 4.7.4~git20120202) but 4.7.4~git20120125-0maemo1+0m7 is to be installed Depends: libqt4-m20120202) but 4.7.4~git20120125-0maemo1+0m7 is Depends: libqtcort20120125-0maemo1+0m7 is to be installed Depends: libqtgui20120125-0maemo1+0m7 is to be installed E: Unmet dependencies. Try 'apt-get -f install'on). ~ #