Some of you may encounter the message 403 Forbidden during Ubuntu Gutsy Security update, especially when you does your update using “sudo apt-get upgrade”.
The message was displayed because the Ubuntu team deliberately block security updates from the server side following reports that the updates are breaking xorg-server package (this very same incident also happened last year, during Dapper release).
Thankfully the issue has been handled by the Ubuntu team, and now you can continue updating your computer without any interruption or side effects from installing the security updates.
Was Ubuntu the only distro affected by this problem?
Credit to enforcer, now I know there are several other distro (OpenSuSE, Gentoo, Debian) besides Ubuntu that experienced this problem.
Should I install any security updates ?
It highly advisable to install security updates whenever they are available from the update server. Failure of doing so may expose your system to various security holes and vulnerability which can lead to your system being compromised by malicious party.