Melody,
I don't have the answers for you, but some further thoughts. I posted last
summer about a baby who changed colors (not as a result of stress!) and whose
ability to suck seemed to come and go. She was hospitalized for 5 days,
during which time she hit bottom and then spontaneously improved on her own.
In the meantime,  several work-ups were done on her that were ultimately
inconclusive. This baby took 3-5 months to begin to support herself with
nursing, and was in the meantime alternately fed at breast and finger-fed
(baby was not able to utilize SNS--- never pulled milk from it!).   Neither
neurologist nor pediatrician nor cardiologist nor geneticists could explain
the problem.  This mom kept asking anyone remotely qualified for more clues.
The one answer she did get came from a family doc, who hypothesized that baby
was born with a possible incomplete error of enzymes that self-corrected over
time?  At one point, tests indicated a possible genetic error, but simply
never came through clearly.  If there is such a thing as a partial genetic
error that the body can overcome, then this may have been it. Your baby
sounds like a similar mystery baby, though more severe than the one I dealt
with. Something is wrong!  Babies are born to be able to breastfeed, and when
they can't, we need to ask why.  Kudos to your mom for working so hard with
the SNS; I hope she doesn't stop pursuing better answers.

-Lisa Marasco, BA, LLLL, IBCLC