forcemonkey, LSW2 sometimes glitched the 100% achievement and you had to finish one more level (any level) to unlock it. Maybe it will work in LSW TCS.
Try freeplay: enter mission - exit&save, if that doesn't work just finish the mission properly. Maybe that's the case.
Edit: dude, I see the 100% achievement on your gamercard, it probably didn't popup when you finished RoTJ.