you mean the free cam is blocked 10m above ground? then go into the *.cam files to fix this. there are the limitations for the cams...i guess...may somebody correct me
upps. just saw you meant something else...this must has to do with collision boxes. they are set wrong...the ground is defined to "high"...but i dont know, where the collision of world parts and enviroment is set...maybe in the scene.dat? i dont know...