I found the same thing, to my dismay. I had to return my pair to NCIX in Canada when I discovered the subtle sound of voice coil rub in the left transducer. A little more careful analysis with a swept mono sine wave uncovered a poor left/right tracking, too, evidenced by the signal veering strongly off to the left at high and low frequencies. The mid range stayed centered, though.
After I returned them for replacement (because I really do like the fundamental sound and the configuration is very hard to substitute with another brand or model) I found out that they were sold out of both versions of the 1350 - coiled and straight cord.
I accepted a refund, and now have to buy a pair through some US outlet. When I checked, I found to my disappointment that the selling price had risen $100, so I will wait for it to come back down.