failed to fetch sources during upgrade

[Stormbringer]

Binary package hint: update-manager

While attempting to upgrade from Karmic 9.10 to Lucid 10.04, the update manager (version 1:0.134.7) reported:

Error during update
A problem occurred during the update. This is usually some sort of network problem, please check your network connection and retry.

W:Failed to fetch http://ppa.launchpad.net/kubuntu-experimental/ppa/ubuntu/dists/lucid/main/binary-amd64/Packages.gz 404 Not Found
, W:Failed to fetch http://ppa.launchpad.net/kubuntu-experimental/ppa/ubuntu/dists/lucid/main/source/Sources.gz 404 Not Found
, W:Failed to fetch http://ppa.launchpad.net/network-manager/ppa/ubuntu/dists/lucid/main/binary-amd64/Packages.gz 404 Not Found
, W:Failed to fetch http://ppa.launchpad.net/network-manager/ppa/ubuntu/dists/lucid/main/source/Sources.gz 404 Not Found
, E:Some index files failed to download, they have been ignored, or old ones used instead.

[Jean-Baptiste Lallement (jibel)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. Could you please add the log files from '/var/log/dist-upgrade/' to this bug report as separate attachments? Thanks in advance.

[Jean-Baptiste Lallement (jibel)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future.
To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New".
Thanks again!