We too have been having this issue and we have been dealing with it by either swapping them out or turning them off in game and turning them back on. In fact we have to turn them off and turn them back on anyway because the gun that will select the game or input their name doesn't work until we do.
Arizona Sunshine also just stopped loading up and will crash out on one of our machines. There was a GPU update today, I'm going to roll that back after people are done with it and see if it will work then.
Only has started happening since last night.
