It is fairly common for people to skip a size somewhere along the line, although which size exactly seems to vary from person to person depending on what diaper they're using and the size/shape of their baby. It's definetly usually one of the smaller sizes, usually small, medium or medium-large... ME covers are pretty flexible in their sizing so that even if a cover is bigger than it really needs to be, you can usually just make do and you won't have any real problems like leaks or anything (it just might look a little baggy and big).

The size range on the x-small and small may be the same but they are not the same size at all. The small is made bigger to accomodate the bulk of the One-Size diaper on a newborn while the x-small is made only for prefolds or newborn Sandy's.

Karen.