package gnome-icon-theme 2.31.0-0ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2

[Hamir cyberfreak Shekhawat]

while i was trying to downgrade gnome 3 in ubuntu 11.04.....using "sudo ppa-purge ppa:gnome3-team/gnome3" after some time this was shown "Errors were encountered while processing:
 gnome-icon-theme
 evince
 evolution
 empathy
 rhythmbox
 gnome-control-center
 evolution-exchange
 rhythmbox-plugin-cdrecorder
 rhythmbox-plugins

Warning: Something went wrong, packages may not have been reverted"
please help me out of this.....

ProblemType: Package
DistroRelease: Ubuntu 11.04
Package: gnome-icon-theme 2.31.0-0ubuntu2
ProcVersionSignature: Ubuntu 2.6.38-14.58-generic 2.6.38.8
Uname: Linux 2.6.38-14-generic i686
Architecture: i386
Date: Wed May 9 08:59:21 2012
ErrorMessage: subprocess installed post-installation script returned error exit status 2
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
PackageArchitecture: all
SourcePackage: gnome-icon-theme
Title: package gnome-icon-theme 2.31.0-0ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2
UpgradeStatus: Upgraded to natty on 2012-05-05 (3 days ago)