Problem with apt-get update

[Paul E Condon <pecondon@mesanetworks.net>]

When attempting to run apt-get update, I get the following error

Reading Package Lists... Error!
E: Dynamic MMap ran out of room
E: Error occured while processing python-vtk (NewVersion1)
E: Problem with MergeList /var/lib/apt/lists/cmn:9999_debian_dists_testing_main_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.
big:~#

I suppose that I need to increase the storage allocated to 
Dynamic MMap, but how do I do that? Where is it set? 

TIA

-- 
Paul E Condon           
pecondon@mesanetworks.net