I think that may be the case too. I thought that may be the case, the definition for skill is the one I listed above as "goal directed movement activities" and abilities as "A general trait or capacity of an individual that helps determine a person???s achievement potential for the performance of specific skills" from Magill (2004), Motor Learning: Concepts and Applications
It helps when the author of the book you cited and one of the leaders in motor learning research was on my PhD committee.
As an aside, Magill is a fantastic teacher and he will be one of the Level 3 instructors at next year's Coaches Ed shool. If you (directed to everyone not Dan) can go I'd highly recommend it.