i have the same problem my software manager is not working but when i try to use the terminal all i get is this
Depends: libsmpeg0 but it is not going to be installed
libavcodec53 : Depends: libavutil51 (< 4:0.8.1-99) but 4:0.8.4-0ubuntu0.12.04.1 is to be installed or
libavutil-extra-51 (< 4:0.8.1.99) but it is not going to be installed
libavformat53 : Depends: libavcodec53 (>= 4:0.8.4-0ubuntu0.12.04.1) but 4:0.8.1-0ubuntu1 is to be installed or
libavcodec-extra-53 (>= 4:0.8.4) but it is not going to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).
if i could get some help that would be great