Hello,
Finally found a solution : Manfrotto has released an adaptator specifically designed for the524 remote and Panasonic HPX300 as Fujinon has changed the pin connections : the adaptator cost only 20€ and reference is R524,97 (adap.CAB. FUJIXT17x4,5BRM-K14). thanks to Valery Cahuzac from PBS Paris who solved this for me!
Franck Villano