On a lenovo notebook running precise with quantal LTS stack has this issue. When connecting through VGA port, laptop monitor and external monitor will enter extend mode. But after pressing FN+F3 to switching mode, both laptop monitor and external monitor will become black screen, and system is hang, you need to force to power off. When connecting external monitor through HDMI, everything is OK.
On a lenovo notebook running precise with quantal LTS stack has this issue. When connecting through VGA port, laptop monitor and external monitor will enter extend mode. But after pressing FN+F3 to switching mode, both laptop monitor and external monitor will become black screen, and system is hang, you need to force to power off. When connecting external monitor through HDMI, everything is OK.
CPU: Intel(R) Core(TM) i3-4000M CPU @ 2.40GHz
GPU: Intel Corporation Haswell Integrated Graphics Controller [8086:0416]