perhaps you binded it with too many influences?
you can go into the component editor window and i think you can lock the wieghts on certain verts.
sometimes it's easier to use the component editor than painting weights sometimes it's the other way around.
but that might resolve your issue
that's a "Ch" pronounced as a "K"
Computer skills I should have:
Maya, XSI, Photoshop, AfterEffects, Motion, Illustrator, Flash, Swift3D