SerialEvent() wont work

Another aspect that might explain the problem, do some of you have been confronted to a endianness issue between MEGA, in fact all classic arduino AVR boards and DUE since we go from 8-bits to 32-bits. I've noticed the DUE compiler did check mistake when using INT on AVR so 16bits but if we leave this on DUE, it thinks of 32-bits or something else.