An unresolvable problem occurred while calculating the upgrade

[Sundaravenkataraman]

I tried to upgrade to 12.04 alpha version 11.10, by typing "update-manager -d" from terminal, after completing getting new software channels, I got this error message:
" Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade:
E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

 This can be caused by:
 * Upgrading to a pre-release version of Ubuntu
 * Running the current pre-release version of Ubuntu
 * Unofficial software packages not provided by Ubuntu

If none of this applies, then please report this bug using the command 'ubuntu-bug update-manager' in a terminal."

For your more info, I've attached some screenshots...

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: update-manager 1:0.152.25.5
ProcVersionSignature: Ubuntu 3.0.0-15.25-generic 3.0.13
Uname: Linux 3.0.0-15-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu4
Architecture: i386
Date: Sat Feb 18 00:14:05 2012
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
PackageArchitecture: all
SourcePackage: update-manager
UpgradeStatus: Upgraded to oneiric on 2012-02-17 (0 days ago)

[RedSingularity (redsingularity)]

The package libiodbc2 looks like its giving a problem. Post the output of:

apt-cache policy libiodbc2

Thanks.
---
Ubuntu Bug Squad volunteer triager
http://wiki.ubuntu.com/BugSquad

[Jean-Baptiste Lallement (jibel)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 901638, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.