So, my 104 Filco Ninja has rubber on the feet, and instead of preventing the board from moving, it just makes the left foot collapse. I can remove the rubber from the feet so they will slide instead of collapse, but then there is hardly any traction at all. Are there any quick fixes to the collapsing? It seems like if they were angled just slightly more they wouldn't collapse so easily. It's only one foot, is this a defect?