I have installed from scratch ubuntu GNOME 14.04 with gnome-flashback on my old HP HDX 16 laptop (core 2 duo p8600 + nvidia GT9600M + 4GB of ram) and I have problems with the HDMI output (I use it to extend my desktop on a dell U2412M 1920x1200 monitor). In the following I summarize the configurations that I have tried:

1. Using the open source nouveau drivers, only the laptop monitor works, no signal from the external monitor connected to the HDMI output. However, the output of the xrandr command show that the HDMI output is connected with the correct resolution 1920x1200 (I find this thing really weird).

2. Nouveau drivers with VGA connection works without problems on the external monitor, but the image is blurry compared to the HDMI connection.

3. Using the nvidia drivers (I have tried different versions: nvidia-331-updates and the xorg-edgers versions nvidia-334 and nvidia-337) the HDMI output works, but I have system instabilities, random crashes and display freezes. I can't even enter in terminal mode with ctrl-alt-f1, so I have to manually shut down the laptop with the power button.

I really would like to use the HDMI output with the nouveau drivers to avoid the system instabilities that I experienced with the nvidia drivers, but I can't figure out how to make it works.

Alessandro