Bug#385685: Some investigations later...

[Mike Hommey]

After some investigations, it appears the Automatically save changes to
session doesn't do what I thought it did.

It actually saves in real time the changes to the current session, thus
the current behaviour.

Which means there are actually 2 different problems :
- Unchecking the option should remove gnome-session-properties from the
  current saved session. It doesn't make sense to have it in the last
  automatically saved session. Since the only way to disable the mode is
  to launch the properties panel (well, you still can do it from command
  line or gconf-editor, but the only "proper" way is to go in the
  properties), gnome-session-properties is damned to appear in the
  session.

- Somehow, after unchecking the option, the nautilus launch is different
  and opens a new ${HOME} window, which is not supposed to happen.

Mike