Had a nice couple of hours on TSW this afternoon. Enjoyable time running the Tees shunting line and also learning more about the game and locos too. Then FREEZE!. The screen locked and either the xbox console or TV emitted an ear piercing screeching sound. I would normally wait a while to see if a game resets itself, but the noise made me hit the off button. Lost a few hours of gameplay an XP. This is the first time that the game has locked whilst playing. I understand that these things can happen. If anything the occurrence has reminded me to maybe save the game at regular times during play. Maybe every 15-20 minutes or so.