I had the exact same problem mate, and im 100% sure I didnt have this illusive plug that is poorly designed the wrong way round.
You cant actually plug it in the wrong way round imo, it just doestnt seem to plug in far enough (perhaps the design of the connector has changed as it will not locate trying the other way around)
I too would love to find out how you get this to work, like you say there is three things to connect how can one possibly get it wrong?
edit: is the one you can possibly plug in the wrong way round the one that actually plugs into the car, or the extra loom part that daisy chains into the throttle controller?