The Watchdog Timer is broken for both v5 and the v6 series.
The “watchdog-timer=no” does not have any effect as long as there a watch-address to play with - it still tests the watch-address availability and will reboot the unit.
To truly get rid of the watchdog timer I have to remove watch-address as well.
watch-address
and
watcdog-timer are completely unrelated.
See description on what each of them do in the manual
http://wiki.mikrotik.com/wiki/Manual:System/Watchdog
Fine.