Gentlemen,

I'm a ubuntu jaunty user recently changed to Karmic. I'm using a network under a proxy (10.0.0.21 in port 3128 ) which requires an authentication. Both in bashrc and in GUI proxy settings I've added the authentication details. The package managing is working fine when it's done through commands in terminal. But, when using the GUI tools (update-manager, Synaptic, Software Center) it raises a 407 proxy error.

And torrent downloading is not working with Transmission while with Ktorrent it's doing good. Please guide me through these cases...

Transmission has had problems. Mainly with reporting garbage download values to trackers - a big problem on private ratio-enforcing trackers, where the bug will mean the user cannot download anything. I wouldn't use it.