It may or may not be relevant, but I have noticed that my in-game sound has stopped working, then shortly after is when the game will crash. I 'think' this was the case on all three of my lock-ups/freezes, Event 41 Kernel issues.

After I hold the power button down to get my machine to reboot and it comes back up, the sound is working in game again.

For the record, my system sound is always working fine, because I am in Mumble chatting with friends while gaming. I was every time I got the Event 41 Kernel issue in game and Mumble sound was working just fine.