Only one resolution for a laptop screen, cannot change it

I have a Dell Latitude E6410 laptop with a 1440x900 screen. Before updating to Ubuntu 12.10, I could choose
from a number of resolution for the laptop screen, e.g. 800x600, 1024x768, for example through nvidia-settings.
After upgrading to Ubuntu 12.10, only 1440x900 is offered in either nvidia-settings or xrandr.
For example, when the beamer only supports 1024x768, I cannot set the same resolution for the laptop screen.
This is a problem when I want to attach a beamer to my laptop for presentations and clone the two displays, so that I see exactly the same thing on both screens.
What happens is that the screens are cloned but only part of the laptop screen is visible on the beamer.

For an external monitor I can choose from a number of resolutions offered, no problem. But not for the internal display.

The graphics card is identified as NVS 3100M/PCIe/SSE2, VBIOS version 70.18.53.00.04, nvidia driver version 310.14

I first reported this as a question (https://answers.launchpad.net/ubuntu/+source/xserver-xorg-video-nv/+question/214899)
but I got no reply that helped and there was no reaction for several days, that's why I am submitting this as a bug.
Please look there for the detailed configuration and log file output.

I believe this is a bug because it used to work before the upgrade.

How to reproduce the problem:

On Dell Latitude E6410 laptop with a 1440x900 screen and NVIDIA card, run nvidia-settings , go to "X Server Display Configur ation" and to "Resolution". Only "1440x900" is offered. Alternatively, run "xrandr -q".

Expected results:

Other resolutions such as 1024x768 or 800x600 or 640x480 should also be offered and it should be possible to switch to those modes.

Thank you.

Jan