I have a laptop with a nvidia optimus graka. I'm also useing a 23" external monitor. It never really worked... . After installation (it was a clean installation) the 23" monitor worked as it should, but the LCD from the laptop wasn't at the right resolution. And every time i tried to change this the PC crashed.
Today i had a litle bit of time so i decided to solve this problem. I've tried a few things ( e.g. I've installed bumblebee with the nvidia driver and tested it. It's working...) but nothing solved my problem.
Instead of getting any closer to the solution, it's gotten even more strange now... . Now, the display setting isn't recognizing a 2nd monitor at all. But I get on the 23" monitor (which is not shown in the display setting) a screen with the same resolution as the one on the laptop.
The display settings looks so:

Any help would be wonderful.