Bug#159016: apt-get: E: Dynamic MMap ran out of room

[Marcin Owsiany <porridge@debian.org>]

Package: apt
Version: 0.5.4
Severity: important

porridge@melina:~$ sudo apt-get update
Hit ftp://sunsite.icm.edu.pl sid/non-US/main Packages                                       
[...]
Hit ftp://mirror.ipartners.pl woody/non-free Release
Reading Package Lists... Error!
E: Dynamic MMap ran out of room
E: Error occured while processing libdb3 (NewFileVer1)
E: Problem with MergeList /var/lib/apt/lists/debian.mps.krakow.pl_debian_dists_woody_main_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.
porridge@melina:~$ free
             total       used       free     shared    buffers     cached
Mem:        256232     248096       8136          0      11800     177976
-/+ buffers/cache:      58320     197912
Swap:        97772      32020      65752
porridge@melina:~$ ls -l /var/lib/apt/lists/debian.mps.krakow.pl_debian_dists_woody_main_binary-i386_Packages
-rw-r--r--    1 root     root      6535222 2002-07-19 21:33 /var/lib/apt/lists/debian.mps.krakow.pl_debian_dists_woody_main_binary-i386_Packages
porridge@melina:~$ 

Could that be because I have more than 100 sources in my sources.list?
Did it run out of memory?

-- System Information:
Debian Release: testing/unstable
Architecture: i386
Kernel: Linux melina 2.4.18-melina1 #1 nie mar 24 21:19:03 CET 2002 i686
Locale: LANG=pl_PL, LC_CTYPE=pl_PL

Versions of packages apt depends on:
ii  libc6                        2.2.5-14    GNU C Library: Shared libraries an
ii  libstdc++2.10-glibc2.2       1:2.95.4-11 The GNU stdc++ library

-- no debconf information