I have used many types of yo-yos, like the Duncan Imperial and the Duncan Butterfly, and my most recent one, the Duncan Mosquito. I can easily get the speed for the sleeper, but when I try in on wood floor, linoleum,and even concrete( I know, I'm bad!), and instead of the smooth motion that it is supposed to have, I alway get it to be bumpy, like it is jumping on the floor. Am I doing somethin wrong in my technique?