sylpheed-claws-gtk2-plugins: Installation impossible due to errors

I installed sylpheed-claws-gtk2 on my Dapper computer. Then I tried installing sylpheed-claws-gtk2-plugins using Synaptic.

The installation terminates with the following error messages:

E: clamav-base: subprocess post-installation script returned error exit status 1
E: clamav-freshclam: dependency problems - leaving unconfigured
E: clamav: dependency problems - leaving unconfigured
E: sylpheed-claws-gtk2-clamav: dependency problems - leaving unconfigured
E: sylpheed-claws-gtk2-plugins: dependency problems - leaving unconfigured

The following is what was visible in the "terminal" in synaptic when installation was complete:
Preconfiguring packages ...
Selecting previously deselected package libgtk1.2-common.
(Reading database ... 74537 files and directories currently installed.)
Unpacking libgtk1.2-common (from .../libgtk1.2-common_1.2.10-18_all.deb) ...
Selecting previously deselected package libglib1.2.
Unpacking libglib1.2 (from .../libglib1.2_1.2.10-10.1build1_i386.deb) ...
Selecting previously deselected package libgtk1.2.
Unpacking libgtk1.2 (from .../libgtk1.2_1.2.10-18_i386.deb) ...
Selecting previously deselected package libclamav1.
Unpacking libclamav1 (from .../libclamav1_0.88.2-1ubuntu1.1_i386.deb) ...
Selecting previously deselected package clamav-base.
Unpacking clamav-base (from .../clamav-base_0.88.2-1ubuntu1.1_all.deb) ...
Selecting previously deselected package clamav-freshclam.
Unpacking clamav-freshclam (from .../clamav-freshclam_0.88.2-1ubuntu1.1_i386.deb) ...
Selecting previously deselected package clamav.
Unpacking clamav (from .../clamav_0.88.2-1ubuntu1.1_i386.deb) ...
Selecting previously deselected package libdigest-sha1-perl.
Unpacking libdigest-sha1-perl (from .../libdigest-sha1-perl_2.10-1_i386.deb) ...Selecting previously deselected package libdigest-hmac-perl.
Unpacking libdigest-hmac-perl (from .../libdigest-hmac-perl_1.01-3_all.deb) ...
Selecting previously deselected package libgpgme11.
Unpacking libgpgme11 (from .../libgpgme11_1.1.0-1_i386.deb) ...
Selecting previously deselected package libhtml-tagset-perl.
Unpacking libhtml-tagset-perl (from .../libhtml-tagset-perl_3.10-1_all.deb) ...
Selecting previously deselected package libhtml-parser-perl.
Unpacking libhtml-parser-perl (from .../libhtml-parser-perl_3.48-1_i386.deb) ...Selecting previously deselected package liburi-perl.
Unpacking liburi-perl (from .../liburi-perl_1.35-1_all.deb) ...
Selecting previously deselected package libnet-ip-perl.
Unpacking libnet-ip-perl (from .../libnet-ip-perl_1.24-1_all.deb) ...
Selecting previously deselected package libnet-dns-perl.
Unpacking libnet-dns-perl (from .../libnet-dns-perl_0.53-2_i386.deb) ...
Selecting previously deselected package libnet-cidr-lite-perl.
Unpacking libnet-cidr-lite-perl (from .../libnet-cidr-lite-perl_0.15-1_all.deb) ...
Selecting previously deselected package libmail-spf-query-perl.
Unpacking libmail-spf-query-perl (from .../libmail-spf-query-perl_1.997-3_all.deb) ...
Selecting previously deselected package libsocket6-perl.
Unpacking libsocket6-perl (from .../libsocket6-perl_0.17-1_i386.deb) ...
Selecting previously deselected package spamassassin.
Unpacking spamassassin (from .../spamassassin_3.1.0a-2ubuntu1.1_all.deb) ...
Selecting previously deselected package sylpheed-claws-gtk2-clamav.
Unpacking sylpheed-claws-gtk2-clamav (from .../sylpheed-claws-gtk2-clamav_2.1.1-1ubuntu1_i386.deb) ...
Selecting previously deselected package dillo.
Unpacking dillo (from .../dillo_0.8.5-4ubuntu2_i386.deb) ...
Selecting previously deselected package sylpheed-claws-gtk2-dillo-viewer.
Unpacking sylpheed-claws-gtk2-dillo-viewer (from .../sylpheed-claws-gtk2-dillo-viewer_2.1.1-1ubuntu1_i386.deb) ...
Selecting previously deselected package sylpheed-claws-gtk2-doc.
Unpacking sylpheed-claws-gtk2-doc (from .../sylpheed-claws-gtk2-doc_2.1.1-1ubuntu1_all.deb) ...
Selecting previously deselected package sylpheed-claws-gtk2-pgpmime.
Unpacking sylpheed-claws-gtk2-pgpmime (from .../sylpheed-claws-gtk2-pgpmime_2.1.1-1ubuntu1_i386.deb) ...
Selecting previously deselected package sylpheed-claws-gtk2-pgpinline.
Unpacking sylpheed-claws-gtk2-pgpinline (from .../sylpheed-claws-gtk2-pgpinline_2.1.1-1ubuntu1_i386.deb) ...
Selecting previously deselected package sylpheed-claws-gtk2-spamassassin.
Unpacking sylpheed-claws-gtk2-spamassassin (from .../sylpheed-claws-gtk2-spamassassin_2.1.1-1ubuntu1_i386.deb) ...
Selecting previously deselected package sylpheed-claws-gtk2-trayicon.
Unpacking sylpheed-claws-gtk2-trayicon (from .../sylpheed-claws-gtk2-trayicon_2.1.1-1ubuntu1_i386.deb) ...
Selecting previously deselected package sylpheed-claws-gtk2-plugins.
Unpacking sylpheed-claws-gtk2-plugins (from .../sylpheed-claws-gtk2-plugins_2.1.1-1ubuntu1_all.deb) ...
Setting up libgtk1.2-common (1.2.10-18) ...

Setting up libglib1.2 (1.2.10-10.1build1) ...

Setting up libgtk1.2 (1.2.10-18) ...

Setting up libclamav1 (0.88.2-1ubuntu1.1) ...

Setting up clamav-base (0.88.2-1ubuntu1.1) ...
Adding system user `clamav'...
Adding new group `clamav' (114).
Adding new user `clamav' (114) with group `clamav'.
Not creating home directory `/var/lib/clamav'.
dpkg: error processing clamav-base (--configure):
 subprocess post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of clamav-freshclam:
 clamav-freshclam depends on clamav-base (= 0.88.2-1ubuntu1.1); however:
  Package clamav-base is not configured yet.
dpkg: error processing clamav-freshclam (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of clamav:
 clamav depends on clamav-freshclam | clamav-data; however:
  Package clamav-freshclam is not configured yet.
  Package clamav-data is not installed.
  Package clamav-freshclam which provides clamav-data is not configured yet.
dpkg: error processing clamav (--configure):
 dependency problems - leaving unconfigured
Setting up libdigest-sha1-perl (2.10-1) ...
Setting up libdigest-hmac-perl (1.01-3) ...
Setting up libgpgme11 (1.1.0-1) ...

Setting up libhtml-tagset-perl (3.10-1) ...
Setting up libhtml-parser-perl (3.48-1) ...
Setting up liburi-perl (1.35-1) ...
Setting up libnet-ip-perl (1.24-1) ...
Setting up libnet-dns-perl (0.53-2) ...
Setting up libnet-cidr-lite-perl (0.15-1) ...
Setting up libmail-spf-query-perl (1.997-3) ...
Setting up libsocket6-perl (0.17-1) ...

Setting up spamassassin (3.1.0a-2ubuntu1.1) ...
SpamAssassin Mail Filter Daemon: disabled, see /etc/default/spamassassin

dpkg: dependency problems prevent configuration of sylpheed-claws-gtk2-clamav:
 sylpheed-claws-gtk2-clamav depends on clamav; however:
  Package clamav is not configured yet.
dpkg: error processing sylpheed-claws-gtk2-clamav (--configure):
 dependency problems - leaving unconfigured
Setting up dillo (0.8.5-4ubuntu2) ...

Setting up sylpheed-claws-gtk2-dillo-viewer (2.1.1-1ubuntu1) ...
Setting up sylpheed-claws-gtk2-doc (2.1.1-1ubuntu1) ...
Setting up sylpheed-claws-gtk2-pgpmime (2.1.1-1ubuntu1) ...
Setting up sylpheed-claws-gtk2-pgpinline (2.1.1-1ubuntu1) ...
Setting up sylpheed-claws-gtk2-spamassassin (2.1.1-1ubuntu1) ...
Setting up sylpheed-claws-gtk2-trayicon (2.1.1-1ubuntu1) ...
dpkg: dependency problems prevent configuration of sylpheed-claws-gtk2-plugins:
 sylpheed-claws-gtk2-plugins depends on sylpheed-claws-gtk2-clamav; however:
  Package sylpheed-claws-gtk2-clamav is not configured yet.
dpkg: error processing sylpheed-claws-gtk2-plugins (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 clamav-base
 clamav-freshclam
 clamav
 sylpheed-claws-gtk2-clamav
 sylpheed-claws-gtk2-plugins
E: Sub-process /usr/bin/dpkg returned an error code (1)
A package failed to install. Trying to recover:
Setting up clamav-base (0.88.2-1ubuntu1.1) ...

Setting up clamav-freshclam (0.88.2-1ubuntu1.1) ...
 * Starting ClamAV virus database updater freshclam [ ok ]
Setting up clamav (0.88.2-1ubuntu1.1) ...
Setting up sylpheed-claws-gtk2-clamav (2.1.1-1ubuntu1) ...
Setting up sylpheed-claws-gtk2-plugins (2.1.1-1ubuntu1) ...

Also, the following might help:
carthik@pablo:~$ apt-cache showpkg sylpheed-claws-gtk2-plugins && apt-cache policy sylpheed-claws-gtk2-plugins
Package: sylpheed-claws-gtk2-plugins
Versions:
2.1.1-1ubuntu1(/var/lib/apt/lists/mirror.mcs.anl.gov_pub_ubuntu_dists_dapper_universe_binary-i386_Packages)(/var/lib/dpkg/status)

Reverse Depends:
Dependencies:
2.1.1-1ubuntu1 - sylpheed-claws-gtk2-clamav (0 (null)) sylpheed-claws-gtk2-dillo-viewer (0 (null)) sylpheed-claws-gtk2-spamassassin (0 (null)) sylpheed-claws-gtk2-trayicon (0 (null)) sylpheed-claws-gtk2-pgpmime (0 (null)) sylpheed-claws-gtk2-pgpinline (0 (null))
Provides:
2.1.1-1ubuntu1 -
Reverse Provides:
sylpheed-claws-gtk2-plugins:
  Installed: 2.1.1-1ubuntu1
  Candidate: 2.1.1-1ubuntu1
  Version table:
 *** 2.1.1-1ubuntu1 0
        500 http://mirror.mcs.anl.gov dapper/universe Packages
        100 /var/lib/dpkg/status

Please let me know if any other information is required. The same problem was experienced earlier on another computer.