Issue with skinning of environment - im floating in the air

There are some points in the arena that I can jump to and stand on that are not really there. This may be something to do with skinning, sprites etc. I have uploaded the screenshots to show a location on the map in which I can jump up and run along an invisible edge. Also, when you jump at an angle and hit this ledge, you collide with the map and you will hear the sound play over and over for the jump/land sound. I can replicate this without much effort. Screens show the ledge I am jumping up to, the angle, and then a few shots looking down at the invisible floor.