Ubuntu extras repository prevents other updates

The reason for that would be that apt errors out when updating sources with extras enabled:

W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/main/source/Sources.lzma 404 Not Found
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/main/binary-amd64/Packages.lzma 404 Not Found
E: Some index files failed to download, they have been ignored, or old ones used instead.

but I think apt behaves as inteded there, so extras should rather be initialized for natty.
Are you talking about updating in update-manager? I can update fine with 'sudo apt-get update; sudo apt-get dist-upgrade' even with extras failing to update.

I can't speak for the others on the forum, but for myself a 'sudo apt-get update; sudo apt-get dist-upgrade' simply didn't upgrade. The update bit appeared to work fine (except for the apt errors you mentioned above) but not the upgrade.

Of course the apt errors for not being able to fetch the extras repository should not cause the whole system to see not updates - that is the bug.

On your system are you able to actually install new updates, or just update the package lists, with the extras enabled? The other thing I note is that my system was running i386, I wonder if that could make any difference.

Thanks for reporting this bug and any supporting documentation. Since this bug has enough information provided for a developer to begin work, I'm going to mark it as confirmed and let them handle it from here.

I have attempted to upgrade daily using "sudo apt-get update" and "sudo apt-get dist-upgrade" for about a week. This effectively blocks all updates. Using update-manager also fails. Commenting out extras in /etc/apt/sources.list shows 225 upgrades on this system.

Thanks for taking the time to make Ubuntu better!

This is partly a problem with extras.ubuntu.com that its not created for natty yet.

The missing natty distribution on extras.ubuntu.com is fixed now.