Ive read in ur tut about gates and bridges but remembered for that only when found reason. Afaik i have only 1 perimeter(when select items in 2d window i choose assign to per. 1, am i right here?
EDIT: I also tried to delete all breaches and pastle on those places terrain - same thing. If behind the gates exists the path - the gates will not work... I will try to place bridges before the gates. It will make my settlement bigger and maybe will make some disbalance - to capture gate units should pass bridge. Bridge in this case - limited space, isn't it?