before you tighten the bolt make sure to hammer the scs down onto the fork with a mallet. the bolt isnt to make the headset tight its to stop it from getting loose. then tighten the compression bolt and hit the top of the scs again, and tighten the compression bolt again. then put the bars on and tighten the bolts.
i had the problem...
it was that my star nut was slipping inside my fork so i just super glued the star nut in there so it didn't move anymore and it works perfect now