"It was not possible to calculate the update"

[Marsil]

A warning icon apperead in the top bar, and the message below were there (I translated it to english because my pc is in portuguese):

"An impossible to solve problem ocurred when calculate the update.

Please, report the error of the package 'update-manager' and include the following error message:
'E:Error, pkgProblemResolver::Resolve generated fails, this may be caused by hold packages' "

original message:

"Um problema impossível de se resolver ocorreu enquanto calculava a atualização.

Por favor reporte esse erro do pacote 'update-manager' e inclua a seguinte mensagem de erro:
'E:Erro, pkgProblemResolver::Resolve gerou falhas, isto pode ser causado por pacotes mantidos (hold).'

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.10
ProcVersionSignature: Ubuntu 3.2.0-22.35-generic 3.2.14
Uname: Linux 3.2.0-22-generic x86_64
ApportVersion: 2.0-0ubuntu4
Architecture: amd64
Date: Thu Apr 12 23:03:33 2012
ExecutablePath: /usr/bin/update-manager
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
SourcePackage: update-manager
UpgradeStatus: Upgraded to precise on 2012-04-05 (7 days ago)