Ubuntu – Upgrade Ubuntu 10.04 to Ubuntu 10.10

I'm new to these forums so I'll be quick.

When I try to upgrade to Ubuntu 10.10 from 10.04 I get this error, I have tried upgrading from Terminal and Update Manager as well.

Could not determine 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 against the
'update-manager' package and include the files in
/var/log/dist-upgrade/ in the bug report.
Restoring original system state
Thanks
Aborting