The fringe around the hair looks fine, so I'm guessing it's not nozzle drop out. It is probably a profile issue - looks reversed. This usually happens when the media profile isn't sure how to handle building black. From personal experience, this is usually caused by a disconnect between the profile and the linearization - the profile thinks that it is building a combination black, but it does not have enough ink to pull from in the linearization. I've also seen it caused by changing the total ink limit after the profile is built.
For a quick check I'd try changing the media profile. First thing I'd try to fix the problem would be to relinearize the media profile.
Apologies if this isn't explained too well, brain's a bit scattered today!