When running apt-get update, you may get the following error:
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_quantal-security_universe_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.
Apparently, this is due to some corruption in your local package listing. To fix this, simply delete the listings then rebuild them.
~$ sudo rm /var/lib/apt/lists/* -vf
~$ sudo apt-get update
It'll take a while to completely rebuild, but things should be fine after. The above info was gleaned from this particular forum post.