Had the same experience twice recently, except that it took a lot more time and power cycles to see LED activity and boot up the RT3200 again. This after about 1½ months without any issues, similar to what happened to this user that couldn't/can't boot.
I added echo performance > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor to local startup for now after reading some of this thread. Haven't rebooted since, but may test later. Is there anything else that could be done to prevent this issue?