Follow up - the struts are not the problem - had AA round couple of weeks ago to replace/change the passenger airbag inflator unit (recall from Honda) showed the chap - he recons its a sensor somewhere - he opened it of the fob, it raised to top then beeped and then began to close again - he pushed the button on the tailgate itself as it began to close and the tailgate stopped and stayed there fully open - proving that the motor, wiring and struts are working as they should and pointing to a sensor somewhere as he said - problem is nobody seems to know - including Honda, which to be honest does not surprise me as all they want to do is either charge a fortune and tell you they don`t know and then try to sell you another car - NO faith in Honda and there dealerships !
ANY HELP or ideas welcome, apart from that the car is as near perfect as you can get !