When you do your sweeps and place the profiles outside of the bounds of the path, the sweep command can use whats called "autoplacement" and has the chance to decide the best place for the profiles to fit... When you place then inside of the bounds of the path, the profile we be swept "THERE" as if that exacly where you want it... Placing the profile on the very end, gives no place for the sweep to go to a point.