"Could not calculate the upgrade" - An unresolvable problem occurred while calculating the upgrade: The package 'postgresql-plperl-9.0' is marked for removal but it is in the removal blacklist.

[brandon wilder]

got this message when trying to upgrade ubuntu OS

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: update-manager 1:0.150.5.4
ProcVersionSignature: Ubuntu 2.6.38-16.67-generic 2.6.38.8
Uname: Linux 2.6.38-16-generic x86_64
Architecture: amd64
Date: Mon Nov 5 07:32:01 2012
GConfNonDefault:
 /apps/update-manager/check_new_release_ignore=oneiric
 /apps/update-manager/first_run=false
 /apps/update-manager/show_details=true
 /apps/update-manager/window_size=(600,600)
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: Upgraded to natty on 2012-11-05 (0 days ago)
VarLogDistupgradeApttermlog:

VarLogDistupgradeHistorylog:

VarLogDistupgradeTermlog: