Comment 10 for bug 876839

Proxy settings on oneiric just don't work. I just don't understand how functionality and value was reduced from natty and all its ancestors, and the people are only finger pointing - this bug is similar to that and that bug was addressed by so and so...

There is a button for applying proxies system wide. The button does not work most of the time. It doesn't ask for a sudo password most of the time. It does not modify /etc/environment. It does not create any proxy settings in /etc/apt/conf.d/

It looks like this will *never* be fixed.
Whatever bug you file - it will be similar to some other bug.