Aha! I wondered if that might have something to do with it! I'm not an apple-shaped person, but I did think it was odd that Skinny Butt didn't have the same problem that I did with the ped. I'm a pear shape... well, to be honest, lately I am more of an eggplant thanks to the holidays.
Thanks for the tip! If the next one I get doesn't work, I'll know I have no one but my waist to blame.