I am new to Adobe Edge and I wonder if I can make my symbol play only once on mouseover. I want a picture to appear only when mouse finds it and stay there (I made a symbol in which there's animation of picture appearing from white). Now I only managed to make it appear when it's mouse over, but when my mouse is over the same area again, it plays over again and looks like blinking.
Yes you can use unbind for that. But if you ever need it to work again then you will have to rebind.
Example to unbind a click event
You might also want to try using mouseenter instead of mouseover. Mouseover also fires when you move the mouse, so you'll get some hiccuping/flickering as you mentioned.