Analogue-sequencer

hi list,

I've had trouble today trying to (finally) upgrade to v4
I'm using MidiOX to send the firmware v4 Sysex as downloaded from
Sequentix website today:
- I fire up in Firmware check mode (Func+Page) 
- then I arrive to the " Boot / Flash " option page as said in the manual
- I hit "flash" , the P3 displays  "start F/W TX now" 
- I launch transmission from MidiOX my led MIDI activity blinks on the
interface, so midi data is definitely here.
- no other MIDI cable is plugged into the P3 (apart from the obvious
PC Out - P3 )
- but hey, at the end of the transmission no nothing, nada... the P3
stays and displays "start F/W TX now" ...

any help ? am i doing something wrong ?

regards,
Olivier