Upgrading to 11.10 [Authentication Failed]

[mojon]

Hi, I'm new on ubuntu.
When I'm trying to Upgrade (11.04 -->11.10), I have this problem


Authenticating the upgrade failed. There may be a problem with the network or with the server

How can I fix that?
(internet is working fine)

[Paddy Landau]

Sometimes the repository servers get busy and don't respond. I have noticed this happen much more often, and for longer, since 11.10 was released.

I would wait 24 hours and try again. If it still happens, post again. Be sure to back up all your data before proceeding with an upgrade.