Originally Posted by Kamil
NVidia 660M GPU w/ latest beta drivers
...
Game on Ultra preset, 1080p resolution (chosen by the game's automatic setting button)

The game shouldn't have picked the ultra preset; I missed the 'M' earlier when I glanced at your specs. Check out the performance in a skirmish, but you may have to lower that (don't think that has anything to do with the game freeze, though).