Are the straps set on the small size? Look at the back of the seat where the two shoulder straps connect to the H-shaped metal splitter plate. There are two settings and those seats usually come set on small -- look in your manual for how to move the webbing to the larger setting. I believe you can also adjust at the hips, just make sure to follow the directions in the book (it's not hard).
2/2/11 at 2:18pm