Funny, but I playing normal in this game, but then I exit game, second monitor, attached to my notebook via VGA or HDMI cable (I have two outputs, no matter which one is used), turns off and I ned to go to display setting and turn it back on. No errors are displayed either by game or in terminal console.
I know some games turn it off when they are launched, but this one is the only one I saw turn off on exit 
Can it be game bug?
HP ProBook 4320s
SKU Number: XN864EA#ACB
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02)
Subsystem: Hewlett-Packard Company Device 1423
Kernel driver in use: i915
Kernel modules: i915
3.2.0-26-generic Linux kernel, Ubuntu 12.04 LTS distribution
For example, connected VGA output:
$ xrandr
Screen 0: minimum 320 x 200, current 2390 x 768, maximum 8192 x 8192
LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 294mm x 166mm
1366x768 60.0*+
…
VGA1 connected 1024x768+1366+0 (normal left inverted right x axis y axis) 312mm x 234mm
1024x768 85.0*+
…
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
After game exits VGA1 turn off: no one mode have “*” (mark “selected”) any more, and I need to turn on by command “xrandr --output VGA1 --right-of LVDS1 --auto” (or by graphical interface).