Can anybody help? I'm using the Railing/Fence tool on a site model in '3D Line Mode'. But 9 times out of 10 the Railing/Fence object is being created at Z=0, not on the surface of the site model. The cursor snaps to the contours fine but the fence when it's created is horizontal on the ground plane + the 'Height Point 1' + 'Height Point 2' parameters in the O.I.P. are both 0.   The one exception to this behaviour is ONE particular saved Railing/Fence symbol I have which WILL create on