you will find that both the front doors and the tailgate are not being locked when using the fob. I had the same thing on mine and after reading the wire circuits and understanding the systems it turned out to be the drivers door lock/switch unit.
Other then the cost of the new part the hardest part was trying to get the 3 control arms clipped into the new lock unit. as there is sod all space in the door and all the pressings are as sharp as glass.
locks with the drivers door or lock the drivers door from inside(if it will) and slam lock the passenger door! never come accross it before so its a bit of a guess!