Ipo Drivers scaling problem

Hi there, Ive been setting up some control objects using the ipo connection editor and have just noticed that I have a weird scaling problem. When I connect RotX from the crontrol object to QuatX on the driven object it rotatles about the right axis but not the same ammount, i.e. If i rotate the Control object 90 the bone moves 53.185. I suspect it has something to do with translating Rot to Quat but im not sure exactly how Quat rotations work. I couldnt find regular Rot values in pose mode for the bones. Anyone know where I’m going wrong?