tonearm/cartridge set up question

I'm new to vinyl and recently got the inclination to take a closer look at my set up to see where everything was at. Upon inspection I noticed the dropped counterweight on my JMW 9 arm was slightly off center, it was rotated about the axis formed by the length of the arm when viewed from the front. I adjusted it so it now hangs straight up and down, re-checked VTF and the cartridge (cheap Grado Red) is vertical when viewed from the front now. Problem is that I now notice a slight shift in imaging and soundstage, it's off to the left of center consistantly. I verified this with identical tracks on CD.

Did I screw something up? Should my cartridge not be vertical? I was present when my dealer set up my arm/cartridge and do not remember him making adjustments for this.

Any thoughts?