Anti-GAD postive with gestational diabetes

Hello,

I've tried a couple of other chat boards hoping I would get someone with some familiarity regarding Anti-GAD testing.  
I was diagnosed with gestational diabetes at 24 weeks of pregnancy.  I have never been overweight, but diabetes is prevalent in both sides of my family.  And I also believe that I've always had issues with low blood sugar all my life.
Since the beginning of my pregnancy I have been suffering from some strange muscle stiffness and was sent to neurology for further testing.  One of the tests that they took was that of Anti-GAD.  It came back positive.  One neurologist suggested that that it may have a correlation with my diabetes and maybe not with the muscle stiffness (they are still running tests and trying to get to a diagnosis).
An OB/GYN doctor on the pregnancy chatboard mentioned that Anti-GAD is usually associated with Type I diabetes and not with gestational (which is associated with the development later in life of type II diabetes [not an auto-immune process, but the due to insulin resistance]).
I was wondering if anyone had heard a correlation between Anti-GAD positivity and gestational diabetes.  And what that means post-partum.  Thank you!