I use ubuntu on my company computer. I just switched to 12.04. To avoid network infrastructure limitation I installed it and updated it using a broadband mobile connection.
That connection is ok for this kind of things but for everyday activities I need to be connected to the company network (wired connection) and hook up to the company firewall.
Whenever I activate the proxy (configured automatically by a url with pac file) every network related activity lags down to the point that it feels almost frozen. The wors is of course trying to browse. and it's not just Firefox, the same happens with Chromium.
I previously had ubuntu 10.10 and the proxy connection worked just fine.
Does anyone know how to fix the problem?