Just to help anyone else out there who may experience the same situation. I spoke with Bob on the phone and he said that he has seen this before with some of the limbs that are a little older. He said that it took a few years for the length of the limbs to "settle" to what they are currently, which by the way a 57" string is fine for, with an A riser and D limbs. But Bob said that some of the earlier Shawnee Dakota limbs needed a string a half to 3/4" longer. No worries on my end, I'm just going to order one at 57 1/2" and shoot the heck out of it! Just wanted to mention that the string I ordered was from "Oliverstacy" aka Josh Sowerby and it is an awesome string and exactly the 57" that I ordered. The other strings I ordered from him for other bows fit and function perfect.
Travis