Nonresposive white screen at beginning of Alien missions?

I checked this forum as well as Googled it but couldn't find this problem happening with anyone else! At the start of the Alien mission while it's still at the lab the screen will just at any time suddenly fade to white and stay that way! The game will freeze, only the music continues, and the game can't be paused, only quitting to dashboard is available. For example one time it happened while the doctor guy was telling the Alien which direction to look in while it's still locked up, and another time it happened shortly after the first guy is killed that they send in the room with the Alien.