I'm gonna throw out one alternate possibility that I am beginning to find increasingly likely given the fact that Isidore is "obsessed" with the NNW motion. Here it goes:
Isidore keeps moving NNW overnight, strenthening slowly. Moves quite a bit further east than NHC forecast says (near central Cuba) and weakens some overland. After this, it moves slowly NNW or N along or very near Florida West Coast. Does this as a category one or maybe borderline category two if the landmasses are nice to Izzy.

Heck, it's just a possbility. NHC is either going to live by their forecast or die by it.

Kevin