After several tries on installing radiotray on Ubuntu Oneiric version, another user came up with the trouble being it the software sources settings. Now that i want to perform the installation of radio tray again apt-get is hanged waiting for the suitable packages for radiotray. Can't even end the process in System Monitor.

I've already performed a logout and didn't kill it, probably a restart will do it. Is there any other way to stop apt-get from running when it's waiting for packages to download?