Ground Battle Causes Crash To Desktop

This has happened to me several times. I will invade a planet and the animated sequence screen appears. The land on the planet is all white. Like snow white, no features whatsoever. Just as the battle begins, I crash to desktop and I need to hard shut down to get out of the game. Not sure why it happens but I guess its important to note that it doesnt happen all the time. I would say 1 out of every 6 planet envasions crashes the game. lol, its sorta hard to conquer the galaxy when the game is workin against ya hehe