First off, Mason-Dixon is my favorite pollster, especially when dealing with southern states. Having said that, McCain leads by 21 points among whites in a state where just over 72% of the population is white (acc to 2000 census), and it translates to only a three-point lead? I can't do the math right now, but that does not seem right to me, not at all.
VA can also be considered by same census data to have 74% white population (slightly different measurement).