Comment 117 for bug 1365695

At least two of us (myself and the second poster) were reporting a problem with the Optimus functionality on a Thinkpad W530 where the laptop dock's VGA port is not recognized by Nvidia, but which can be fixed after the downgrade to ubuntu-drivers-common 0.2.91.5. I replicated the problem by upgrading the package and then trying your xserver-xorg-video-intel from the ppa and it did not fix the problem, but I'm pretty sure that we have a separate issue. The issue we're experiencing is the VGA port on the laptop dock (which is controlled by the Intel chipset) isn't recognized by the Nvidia drivers with Optimus enabled for automatic selection.