hi there, I hope your problem was solved.

If your trying to fix the problem still ( like the previous poster said, all the vertices wieght average to 1).....what you can do if still having issues is, first, make sure that toggle hold weights is off for EVERY bone....than select the pelvic bone maybe, and paint a weight of one over the verts that are having the issue.

-Also, after weighting verts to joints...move the joint around a bit to make sure its not pulling verts in other areas (like the foot pulling verts on the neck)....just to be sure paint zero everywhere else (doesnt take long if you increase the brush size)....than toggle hold weights on the joint...than move to the next.

hope that helps