Same issue here,

No particular change (no drivers update, no dayz update) and the issue occurs.
The only thing is geforce experience whitch recognize the game to update graphics.
Since then i've remove the software and the issue goes up.

For me the game never crash.

Even on start i must bring the windows to front for the game to load normaly.
My try:
Update my drivers (to version 335.23) same issue.
Install the experimental version of dayz same issue
gone back to the stable version.
Deleted /user/mydoc/dayz/dayz.cfg the game won't maximize even on start.

The only way for me to access the desktop and then going back to the game is to put the windowed param to 1 in dayz.cfg
So the game can minimize and maximize normaly.