As you probably know, the current experimental build tends to crash randomly during play: Frame freezes, back to desktop, "DayZ is no longer working"
I just found out that this can also happen in the menu. I was back in the main menu after logging out of a server, alt-tabbed the game to minimize it, and had it running in the background for several minutes when the same crash occured, so its not related to anything happening on the server.
Just thought this information might be useful! Cheers :)