upgrade to new 11.10 distribution version fails

[geoffm]

Upgrade to 11.10 fails with: 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.
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Not sure why...

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: update-manager 1:0.150.2
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
NonfreeKernelModules: nvidia
Architecture: i386
Date: Fri Jul 8 13:35:51 2011
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: Upgraded to natty on 2011-07-08 (0 days ago)

[RedSingularity (redsingularity)]

Please attach the directory:

/var/log/dist-upgrade

Thanks.
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[geoffm (geoffm-companionway)]

Attached are all the dist-upgrade logs - the last 2 attempts are the ones where the error occurred - date 20110708.

[RedSingularity (redsingularity)]

It is failing because you have PPA's set up. You need to remove those and their packages. Consider the tool 'ppa-purge' to do this.
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[RedSingularity (redsingularity)]

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