Kpackagekit gone crazy

I have a problem with kpackagekit on 11.2. The program often display a popup to autenticate a proxy connection (BTW, that I’ve never set) for package download; the crazy thing is that, wheter I choose to enter password or to ignore it, it restarts after several minutes… it’s quite annoying… how can I disable it??

Other thing: when I choose to download the update packages, it always doesn’t work, because of the dependencies… I have to use Yast and update manually every time. Isn’t it a bit useless?