Surface to Rib offset issues (vector problems?)

I've been working from iterations of the same definition for a couple of months now, and today for some reason the vectors are messing up right at the beginning of the definition.  It's basically where I perform an offset operation on a number of curves across a surface, which then form the geometry for a series of rib structural members.  It's worked flawlessly previous to this, but just started going weird today.  I suspect it is something to do with me moving up to release .8.0001 from .7.  I've attached the definition and surface.  The problem seems to occur right at the beginning of the definition.  The rest I think can be ignored.  I've tried tracing back for a cause, but am coming up with no solution.