Hedge Trimmers

I just purchased a new Husqvarna 122HD45 hedge trimmer. The unit starts immediately with no problem, however after starting it does not appear to run in the "start throttle position" and the blades do not move. (I am familiar with Husqvarna chain saws and their start throttle position characteristics). While idling, I adjusted the throttle screw from full clockwise to full counter clockwise, with no change observed in the idle speed and the blades remain motionless. At either extreme position, the engine will die. Furthermore, I cannot get the unit to get above idle speed without manipulating the choke - that is, I have to feather the throttle while adjusting the choke on/off until the engine rpm's increase. Once running above idle speed, the trimmer runs fine at various engine speeds until I let it go back to idle. To get above idle, I must once again manipulate the choke/throttle. Any suggestions on how to resolve my throttle issue?