On an Optimus(R) ThinkPad system, the digital output ports on the dock are connected only to the nVidia graphics device. As such, when docked the system can use both graphics devices (Intel integrated and nVidia discrete) to output to four displays. However, when in this configuration, sometimes the display configuration (which displays are active, which is primary, what are their resolutions, etc.) might be lost during the system reboot.
Any of the following ThinkPad systems running on Windows 7 and configured with Optimus(R):
This is a permanent limitation of the operating system. Please refer to the Microsoft Knowledge Base article below for more detail. http://support.microsoft.com/kb/2406828