apt

[Debian User <ernded@mate.polimi.it>]

apt-get update mi dà questi errori

E: Dynamic MMap ran out of room
E: Error occured while processing openafs-client (NewVersion1)
E: Problem with MergeList 
/var/lib/apt/lists/security.debian.org_dists_stable_updates_main_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.

e comun
Che significa?
che debbo fare