"I bought the Zipit Bootie in black a while back and loved wearing them, but I put them on last week and the shoe squeaks. At first I couldn't figure out why, but then I realized it was as if the cushion of the shoe gave way. When I press my right heel down, it feels squishy -- like a sponge. Ah HA! so that's whats causing the noise. I've probably only worn them a couple dozen times as I like to rotate through my shoes quite a bit. Being in sunny So. Cal. sandals have been my go-to whenever possible. Perhaps it just had a poorly made pair, but it certainly makes me wary to purchase another one."