apt-get update "error"

[Steve <sda@our.ca>]

Hello, on adding testing to my source lists (I'm presently on stable), I get the 
following error(s):

Reading Package Lists... Error!
E: Dynamic MMap ran out of room
E: Error occured while processing heimdal-dev (NewVersion1)
E: Problem with MergeList 
/var/state/apt/lists/security.debian.org_debian-security_dists_stable_updates_main_binary-i386_Packages
E: Unable to write mmap - msync (14 Bad address)
E: The package lists or status file could not be parsed or opened.


Does this mean that I need to update `heimdal-dev'?

Thanks for reading.