One of my four lift arms is out of adjustment. The front right arm lifts about an inch or two before the other three. So when u place the door in place...there is a larger space (not open) between the door frame and the roof. Looks odd. I read the manual..and it says to place the pin underneat into another hole setting....one of three. How do I know which other hole o put it in? Trial and error or?? Also. would u suggest using safety poles on my unit? Thks!