Whenever I reboot and login, a window titled "Back Up" and "Connect to Ubuntu One" appears, containing a button named "Sign into Ubuntu One". I don't like Ubuntu One, nor any other proprietary cloud backup service, and I will never use Ubuntu One.
How do I disable it and/or permanently remove it?
I tried all the solutions suggested here, but I still get the window.
I've uninstalled all "Ubuntuone" packages I can find, but this window still appears. Oddly enough, even if I click the button, nothing happens.

