Could not initialize the package information

[jerry roscoe]

When i try to see if there are any updates I go to "Software up to date" and Ubuntu comes up with the Could not initialize the package information > an error in update manager and then asks me to include the following information but when I try to copy the information it won't past into this window??

I'm using Ubuntu 12.04 and it wsa up to date as of about a week ago 6/4 as far as I can remember.

[jerry roscoe (jerryroscoe)]

details of error are >

Encountered a section with no package : header,

E: Problem with Mergelist/var/lib/apt/lists/extra.ubuntu.com_ubuntu_dists_percise_main_binary-i386_packages

The package list or status file could not be opened