Update Manager - Failed to load package list

[youoweadam]

I receive an error message when attempting to open the update manager (as prompted automatically).

Title: backend_helper.py

Header: Failed to load the package list

Body: This is a serious problem. Try again later. If this problem appears again, please report an error to the developers.

Details: E:Encountered a section with no Package: header, E:Problem with MergeList /var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_precise-security_restricted_binary-i386_Packages, E:The package lists or status file could not be parsed or opened.

Additional Information:
Release: Description: Ubuntu 12.04.1 LTS (64bit)

_Cannot provide version of the package, as the package information is what is failing to load._

I expected the update manager to open, new versions of packages to be found and installed.
The update manager window does not open, and I am shown the above error window instead.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Reviewing your bug report it seems that you are experiencing bug 346386. This issue happens when you have tried to update your package information when you are a network that didn't return the right files. This issue can be cleaned up by using the following commands in a terminal:

1.) sudo rm /var/lib/apt/lists/*
2.) sudo apt-get update

Thanks and good luck!

[This is an automated message. I apologize if it reached you inappropriately; please reopen the bug task if it was incorrect.]