Hello Gekker and thank you for the report.
Please attach contents of your C:\Users\*username*\AppData\Local\DayZ to this ticket. In case the files could not be uploaded due to their size, use some kind of cloud site from which we can easily download the files.
Regards,
Geez

Here are my contents of the folder:
http://www.mediafire.com/download/hj5dn89redq4hbe/DayZAppData.zip

Hello Gekker and thank you for providing the files.
It appears that the game crashed due to lack of memory available, we are aware of the current problems with DayZ using up more memory when the game is alt tabbed and we are working on a fix. Currently it is advised to avoid alt tabbing to prevent the game from crashing.
Regards,
Geez

Hello,

just wanted to inform you that the crashes got more frequent since the latest exp update (the one with the cars).
I have been avoiding alt tabbing though sometimes I tab out by accident.
You see, I am using a dual screen setup and binded Mouse4 to my push to talk (Team Speak). Apparently my mouse crusor still goes out of my main screen and onto my second screen while playing DayZ and if I press Mouse4 to talk I tab out.

So far I am crashing 100% of the time DayZ gets tabbed.

Would be nice to have the mouse crusor locked to the screen used by the game until a patch fixes the issue.