"All Objects Will Snap to the Terrain?"

Has anyone else noticed that this tool has changed its behavior? When I move an object from above the terrain toward the terrain, it doesn't appear to me to "snap". It goes right through the terrain if I'm not careful. Only when pulling an object up from below the terrain will it snap to the terrain. Or, if it is already snapped to the terrain, you can move it horizontally and it will remain snapped if you are careful, but it can still go below the terrain if you are not. Is this working as intended? I certainly thought it was better the way it used to be.