Hey GTecX,
This is a very interesting question you asked. My HF-650 have a straight cable and, just as you described - a center that is moved to the right just a bit. This is more obvious with electronic music, where there is a bass drum beat that is a tad off to the right. I also perceive some soundstage effectes better with my right ear.
But,
This is something that I have been dealing with all my life with all the headphones that I ever used, from earbuds to full sized ones. My conclusion was a logical one - my right ear is a bit more sensitive than the left, so when I noticed the same with the Ultrasones, I had no reason do suspect the drivers are mismatched. However, in your case they might be, since both coiled and stright cables should be of the same quality.
Couple of friends of mine tried the Ultrasones and they never complained.
BTW did you get the Trackmasters again, or the DVD Edition?