Nvidia Proprietary Drivers need nvidia-settings to set screen resolution and change other settings. In previous versions of Ubuntu and in other distros to make them permanent (used in every session) you click the “Save to X configuration file”. From Karmic on there is no xorg.conf by default!
As a result, nvidia-settings is not able to save the settings and every time I logged in I had to change the resolution (Phew!!!). Then Sathya helped me. He gave me a link from Ubuntu Forums. Then I did the following to fix the problem: