I had no problem with my Teva flip flops last week, except on Soarin'. I rode it the first time with my shoes on, and I was so concerned with squeezing my toes together and flexing my feet so my shoes wouldn't fall off, I didn't enjoy the ride. So, when we rode it after that, I took them off and put them in the underseat basket. It was really fun riding it barefoot; you almost feel as if you could dip your toes in the water a couple of times. The CM's even tell you to take off loose shoes and either leave them on the floor in front of your seat (they will be there when you "land") or in the underseat basket. And believe me, I was not the only one doing it. We rode Soarin' about five times, and I saw lots of bare tootsies hanging around! Other than that, I wasn't worried about my shoes on any rides.