apt-get unusable

[Joerg Sommer <joerg@alea.gnuu.de>]

apt-get 0.5.4 (woody)

Hello,

after an apt-get update I get this messages:
Reading Package Lists... Error!
E: Dynamic MMap ran out of room
E: Error occured while processing diablo (NewVersion2)
E: Problem with MergeList /var/lib/apt/lists/ftp.de.debian.org_debian_dists_unst
able_non-free_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.

I don't know, what it should tell me. The file seems to be correct and a
new apt-get update changes nothing at this situation. What can I do?
apt-get is unusable and I can't do any security updates!

Joerg.