package openssh-client None [modified: /var/lib/dpkg/info/openssh-client.list] failed to install/upgrade: unable to make backup link of `./usr/bin/ssh' before installing new version

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libfaad2-0 libmp4v2-0 gftp-common libx264-54 linux-headers-2.6.24-16-generic
  linux-headers-2.6.24-16
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  openssh-blacklist openssh-client openssh-server
Suggested packages:
  keychain libpam-ssh molly-guard rssh
The following NEW packages will be installed:
  openssh-blacklist openssh-client openssh-server ssh
0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
Need to get 3100kB of archives.
After this operation, 6722kB of additional disk space will be used.
Do you want to continue [Y/n]? y
Get:1 http://ca.archive.ubuntu.com hardy-updates/main openssh-client 1:4.7p1-8ubuntu1.2 [720kB]
Get:2 http://ca.archive.ubuntu.com hardy-updates/main openssh-blacklist 0.1-1ubuntu0.8.04.1 [2124kB]
Get:3 http://ca.archive.ubuntu.com hardy-updates/main openssh-server 1:4.7p1-8ubuntu1.2 [254kB]
Get:4 http://ca.archive.ubuntu.com hardy-updates/main ssh 1:4.7p1-8ubuntu1.2 [1084B]
Fetched 3100kB in 1min23s (37.3kB/s)
Preconfiguring packages ...
(Reading database ... 178876 files and directories currently installed.)
Unpacking openssh-client (from .../openssh-client_1%3a4.7p1-8ubuntu1.2_i386.deb) ...
dpkg: error processing /var/cache/apt/archives/openssh-client_1%3a4.7p1-8ubuntu1.2_i386.deb (--unpack):
 unable to make backup link of `./usr/bin/ssh' before installing new version: Operation not permitted
dpkg-deb: subprocess paste killed by signal (Broken pipe)
Selecting previously deselected package openssh-blacklist.
Unpacking openssh-blacklist (from .../openssh-blacklist_0.1-1ubuntu0.8.04.1_all.deb) ...
Selecting previously deselected package openssh-server.
Unpacking openssh-server (from .../openssh-server_1%3a4.7p1-8ubuntu1.2_i386.deb) ...
Selecting previously deselected package ssh.
Unpacking ssh (from .../ssh_1%3a4.7p1-8ubuntu1.2_all.deb) ...
Errors were encountered while processing:
 /var/cache/apt/archives/openssh-client_1%3a4.7p1-8ubuntu1.2_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

ProblemType: Package
Architecture: i386
Date: Thu Jul 3 11:49:18 2008
Dependencies:

DistroRelease: Ubuntu 8.04
ErrorMessage: unable to make backup link of `./usr/bin/ssh' before installing new version
NonfreeKernelModules: nvidia
Package: openssh-client None [modified: /var/lib/dpkg/info/openssh-client.list]
PackageArchitecture: i386
SourcePackage: openssh
Title: package openssh-client None [modified: /var/lib/dpkg/info/openssh-client.list] failed to install/upgrade: unable to make backup link of `./usr/bin/ssh' before installing new version
Uname: Linux 2.6.24-19-generic i686