Everytime I try to use a gesture on a page with a youtube vide, the gesture stays on the screen. Like if I try to use the gesture over anything that uses adobe flash, it also happens. You need to fix this man. Adobe change a lot of crap and you might need to fix some stuff.
I have exactly the same problem, it's super annoying, it's the only place where strock it is blocked, and i'm fed up to take care to don't gest in the flash player, and if I did, I have to draw on the line that stayed on the screen -_-"