Makehuman IK movement

Hi guys, first of all i’m a noob!! Secondly i’ve a problem with the MHX FK/IK switch. I’ve a character exported from makehuman with MHX rig and when i switch from FK to IK, and i grap the hand controller to move the arm, only controller moves and the arm doesn’t. I’ve checked IK Influence and is already set to 1, IK switch is on IK and everything seems right. Please anyone can help me? What’s wrong? Thanks:D