apt-get - E: Dynamic MMap ran out of room

["linux china" <chinalinux@gmail.com>]

Hi,

# apt-get update
Get:1 ftp://ftp.linuxforum.net stable/main Packages [4523kB]
Get:2 ftp://ftp.linuxforum.net stable/main Release [95B]
Get:3 ftp://ftp.linuxforum.net testing/main Packages [5645kB]
Get:4 ftp://ftp.linuxforum.net testing/main Release [81B]
Get:5 ftp://ftp.linuxforum.net unstable/main Packages [6072kB]
Get:6 ftp://ftp.linuxforum.net unstable/main Release [82B]
Fetched 16.2MB in 2m54s (93.0kB/s)
Reading Package Lists... Error!
E: Dynamic MMap ran out of room
E: Error occured while processing viewvc-query (NewVersion1)
E: Problem with MergeList
/var/lib/apt/lists/ftp.linuxforum.net_debian_dists_unstable_main_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.

any idea how to fix the error?