I'm not seeing anything in the error logs that point to a problem with US², everything appears to be running correctly up until the point the log cuts off.
It seems like you're running from a laptop, US² can be very taxing on a computer, so it's possible you're having issues with overheating. Check to make sure your laptop's vents are clear and not blocked. (Might help to dust them out as well).
Additionally, you can check the windows event viewer, and look for any red errors. They may point to what caused the computer to shutdown. Provided the PC was able to shutdown cleanly... (You'll be looking for system events in the log)
http://windows.microsoft.com/en-us/windows/what-information-event-logs-event-viewer#1TC=windows-7If the computer didn't shut down cleanly, it's quite likely that there's a hardware / Operating system problem on the computer. At worst, US² should only be capable of generating a blue screen. Not halting the entire machine, or forcing it to restart.