I've noticed that after sprinting a ways while crouched, my character will randomly stand up. I've also noticed, after coming to a stop, my weapon is now lowered. Generally, this is just remedied by re-raising it, but at times it won't come back up and I am forced to and from my pistol to remedy it. Not a game-breaking issue, but I've gotten killed once or twice after running into an entrenched enemy because my weapon was lowered.