Well, it seems like my large female agalma is back to normal, so obviously she did not have the feared zonata disease, and probably this was not a virus related problem at all. Most people that I have discussed my snake with, suggest fungus or bacteria infection, maybe from water or food.
I'll try to put a pic in here for you all to see, but I'm not sure if it'll work.
http://www.repti.net/reptile_picture/Lampropeltis zonata_55066.jpg