Glide prob or what......?

Hello guys !Had now about 4 bigger flights.All off them ,iam using the AP landing with Glide path.Everything went fine as i get about 1000 feet.Then the plane begins slowly cheerking left and rightas it is looking for center the Glide Path.This is mostly resulting that i not get down the RWCenterline , think that`s not normal.Anybody checked out this Prob,too ?Maybe i missing something......Any help......cheerspilotpm