update manager could not initialise the package information

[Chernor]

I was trying to update as usual when i got the error message it is showing me is as follows, i don't know if coz my broadband was not working for a couple of days, the broadband is working now but the update is not

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

and i am using Ubuntu 9.04 Jaunty Jackalope