It might just be a technique problem. I was really good at skipping/skidding on my beater bike with nylon straps, then couldn't skid for **** on my nice bike with leather straps, my front foot was coming out all the time.

After I did it once on the new bike, though, my confidence was restored and now I can skid just fine. I tried really focusing on pushing down with my back foot, even though I feel like I rely on my front more for power. After I got used to skidding on the new bike, my feet stopped coming out. Just think about your legs and not the straps (and really throw your weight forward) and after you do it a few times you'll be fine.