Per this comment, there is no need to set bss_transition for Dawn.
Also worth noting is that you don't even need to set 80211k and 80211v either.
(In my previous reply I mentioned a different reason for setting bss_transition to 0 - that I wasn't using Dawn anymore. I am now using it once again, but still bss_transition is set to zero regardless... or in my case I am simply not including a bss_transition setting in /etc/config/wireless)