Some more simulations and it seems that root stiffness is the key to the problems i'm having. All force obey root stiffness except for momentum. So when any movement starts the hair wants to stay in place (momentum) and this moves the root (altough a high root stiffness should have prevented this) and the other forces  con not counteract this since they all obey the root stiffness. Reducing the root stiffness to near zero solved most of my problems. At least other forces can now actually move the hair.
I will test some more (tomorrow) and when I can confirm this I will report this as a bug.