From Bob McGinn's rating the Packers vs Falcons: http://www.jsonline.com/sports/packe...285318851.html

Sam Barrington (44) joined Matthews in nickel and A.J. Hawk (eight) in base, and Brad Jones (23) was the dime. Barrington's alignments are far from precise. He does play downhill, and is a heavier hitter than Hawk or Jones. His vulnerability in coverage was apparent on a 14-yard pass to Jacquizz Rodgers when he was slow reacting and didn't get through a pick. Jones wasn't a dependable presence in the middle. Hawk didn't see the field until 4 minutes remained in the half.
If you have to play Hawk, why would you pick base when, if he has a strength, its coverage? Whatever is affecting him, the new development has to be his legs or something else affecting his speed.

It would really help if Jones could be passable in coverage, but he seems incapable of improvement.