I definitely replace Sensiva with Stroke-It and it work perfectly since I use Autohotkey to simulate Middle clic with Both L.&R. clic.
But it seems I would see the strokes when I draw them... and never seen them.
It's not really a problem (it make a king of magic...wow) but what is the problem ?
The settings seems OK...
Finally, I found a thread about this on the previous messages.
It seems that Stardock Fences makes some problems with strokeIt...
Unfortunatly I use this softwre...
Thanks to your reply MKairys :-)