I had this problem a few weeks back. Your dependencies are messed up, probably due to something changing in the middle of an update.
What you do is, for each of the packages it breaks, try to manually install the dependency with 'apt-get'. This will likely also break in the same way so repeat until you get to the one that's already installed. Uninstall *that* package. Now when you try again, it should install the latest version.
(ctd)