Problem opening synaptic

[Roger Futter]

As a newcomer to Linux this "old dog " has many new tricks to learn and
I expect this will be the first of many.
When I try to open synaptic I get the following error message:-

E: Encountered a section with no Package: header
E: Problem with MergeList
/var/lib/apt/lists/gb.archive.ubuntu.com_ubuntu_dists_jaunty-updates_restricted_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.
E: _cache->open() failed, please report.

Anyone with any idea how I should proceed?

Thanks in anticipation
-- 
  Roger Futter
  rfutter at mailcan.com