I'm having trouble with the curvature using boundary surfaces. I'm new to surfacing and therefore I'm not sure how efficiently I'm doing it, but regardless I can't figure out this issue I'm having.

http://i.imgur.com/hg0y6Re.jpg

As you can see, for the most part the surfaces all smoothly blend into one another, but there is an anomalous red line cutting through the model that I need to get rid of. I'm using the end of each boundary as a direction guide and ordering them all to be tangent to each other but the surfaces just won't work together.

Is there a way for me to fix it?