vertex groups don't show up

Is there some workaround for bones not showing up in the vertex group box when you do vertex assignment? I have quite a few bones, but there are still 3 blank spaces in the box, but it starts at “h”, rather than at “a”. Would weight painting work for a larger number of bones? I really need all of them.

edit: Nevermind. There are enough slots. If I delete bones it seems to screw it up. I just need to make it through without deleting any bones.