Nic: don't fret, it's normal for them to be all over the place. None of my babies had/have the same percentile score for all their stats. If anything is even vaguely concerning the nurse will tell you... Verity was sent off to a paed just becuase she was the 5th percentile for weight (50th for the other two measurements) and she was fine... and now she eats more than I do and i wonder every day why I ever worried! Remember the charts are also really old (1970's I think) and many people don't even chart their babies, they just observe things as health, activity and what the parents are like (my DH is quite light so all my children are influenced by his genes).