pi@raspberrypi:/$ sudo apt-get update
Hit http://archive.raspberrypi.org wheezy InRelease
Hit http://mirrordirector.raspbian.org wheezy InRelease
Hit http://archive.raspberrypi.org wheezy/main armhf Packages
Hit http://mirrordirector.raspbian.org wheezy/main armhf Packages
Hit http://mirrordirector.raspbian.org wheezy/contrib armhf Packages
Hit http://mirrordirector.raspbian.org wheezy/non-free armhf Packages
Hit http://mirrordirector.raspbian.org wheezy/rpi armhf Packages
Ign http://archive.raspberrypi.org wheezy/main Translation-en_US
Ign http://archive.raspberrypi.org wheezy/main Translation-en
Ign http://mirrordirector.raspbian.org wheezy/contrib Translation-en_US
Ign http://mirrordirector.raspbian.org wheezy/contrib Translation-en
Ign http://mirrordirector.raspbian.org wheezy/main Translation-en_US
Ign http://mirrordirector.raspbian.org wheezy/main Translation-en
Ign http://mirrordirector.raspbian.org wheezy/non-free Translation-en_US
Ign http://mirrordirector.raspbian.org wheezy/non-free Translation-en
Ign http://mirrordirector.raspbian.org wheezy/rpi Translation-en_US
Ign http://mirrordirector.raspbian.org wheezy/rpi Translation-en
Reading package lists... Error!
E: Problem parsing dependency Depends
E: Error occurred while processing libwww-mechanize-perl (NewVersion2)
E: Problem with MergeList /var/lib/apt/lists/mirrordirector.raspbian.org_raspbian_dists_wheezy_main_binary-armhf_Packages
E: The package lists or status file could not be parsed or opened.
pi@raspberrypi:/$
I deleted the file mentioned
sudo rm /var/lib/apt/lists/mirrordirector.raspbian.org_raspbian_dists_wheezy_main_binary-armhf_Packages
And reran the update, but it failed again after the download.