I have 1 x ZF7982 and 2 x R700 APs all in standalone mode in 3 different locations. They are all running version 184.108.40.206.194 and each of them will (seemingly) randomly reboot. This occurs as often as 5 times in a day. It occurs more often when there are many devices connected, or maybe I just notice it more then.
Currently, the log files are only saved in memory, so I don't get to see what caused the kernel panic/reboot. But, when all devices get disconnected I'll wait a minute and connect to the admin. Sure enough, the AP uptime and logs indicate that the device was just rebooted.