On occasion, I connect to a stable branch server only to have the game freeze, and I have to Ctrl+Alt+Delete my way out of it.
At first, I thought this had to do with the server host, but then it started happening on other servers as well, so as far as I can tell, it happens randomly.

It has since the first time I encountered this started happening some time after connecting as well.

Another effect of this is that Steam also freezes completely, in a way that I have only seen after DayZ, and it does not happen with other games that have frozen for me.
The only way to get out of Steam freezing like that was to go into the activity manager and abort all processes related to Steam and DayZ: the DayZ.exe, GameOverlayUI and Steam.exe, though Steam.exe doesn't always abort properly, so then I have to reboot the entire system.

As far as I know, it has nothing to do with my system or connection, as those have been able to support DayZ in the past, and I have since upgraded the hardware, allowing it to run at maximum graphics. Right up until it freezes, DayZ runs great. Some sessions it doesn't freeze at all.