FOUR leads? I may be wrong, but don't dual filament bulbs for tail/brake lighting have THREE contacts: a hot lead for the brake filament, a hot for the taillight filament, and a common ground for both? As a start, why not check the number of contacts on the OEM bulbs vs the LED bulbs? And their locations on the base of the bulbs? Maybe the LED folks sent the wrong bulbs? The fact that the orientation affects the circuit strongly suggests a mismatch. I'm rooting for this to be figured out so I can go out and buy a set of LED's just for my tail/brake lights and front parking lights since those are on the most and would not require messing with the flasher unit!!