Aptitude failing on squeeze with package file problems

[Alan Chandler <alan@chandlerfamily.org.uk>]

I just tried to do an aptitude update on my Debian squeeze server.

I get error message like ...

E: Encounted a section with no Package: header
E: The problem with MergeList 
/var/lib/apt/lists/security.debian.org_dists_stable_updates_main_binary-amd64-Packages
E: The package lists or status file could not be parsed or opened
E: Couldn't rebuild the package cache.

I tried deleting all the files in /var/lib/apt/lists/

and trying again, but it just repeated the message

Is this a glitch with the security.debian.org files today - or something 
more serious.

After this message occurs, you can't do anything other than close aptitude.

I tried Cancel Pending Actions (from the Actions menu) and got a 
segfault in aptitude.

Anyone else seeing anything like this?

--
Alan Chandler
http://www.chandlerfamily.org.uk