I found a solution. you need to use newer avrdude version.
I useed that one http://downloads.arduino.cc/tools/avrdude-6.3.0-arduino17-x86_64-apple-darwin12.tar.bz2 and it works.
You only need to change the command a bit as the conf file is in that zip on different folder.
./avrdude -C ../etc/avrdude.conf -c arduino -p m1284p -P /dev/tty.wchusbserial1410 -U flash:w:os_219_4.hex
maybe Ray can change the documentation for FW updates on MAC and include that informations.