Mesh Collider HELP -

when i import a mesh it comes in fine want i want to use a mesh collider with covex it no longer conforms to the mesh http://img535.imageshack.us/img535/8321/meshg.jpg

HELP PLEASE ITS DRIVING ME INSANE

A convex mesh collider isn't called convex for no reason. Any concavities will of course be filled in. That particular shape would be much better off using two box colliders anyway; there's no reason to use any kind of mesh collider on it.