Screen resolution on Mountain Lion (trying to use 2048x1152)

Question

I recently installed OS X Mountain Lion on a 27'' iMac (late 2009) and I am not able to set the display resolution to 2048x1152 as I did on Lion. In fact, the initial version of Lion didn't allow that resolution but it appeared in the resolution list after a system update (I don't remember which one).

Is there any way of setting the display resolution to 2048x1152 on Mountain Lion?

I have uploaded two screenshots: Resolutions in Lion: http://imageshack.us/photo/my-images/210/reslion.png/ Resolutions in Mountain Lion: http://imageshack.us/photo/my-images/546/resmlion.png/

Thanks in advance.

Answer 1

Hold the option key when clicking "Scaled" to enable more resolutions.

Source.

Answer 2

Thank you for you answer, peelman however that "trick" do not work for me. When I hold the option key (and click "Scaled"), the list shows the same resolutions...

Nevertheless I have found a software that may be useuful: SwitchResX. It allows set up my desired resolution however it is very expensive. Maybe someone can be interested in it...