the first image is the bind pose, i've moved some vertices since then and deleted none deformer history, but these vertices wont follow the bone properly even though they are weighted fully to the shoulder (aqua colored bone). i also have some vertices doing the same on the neck, where they spike out as i bend the neck but they are fully weighted to the neck bone..

how can i fix them? :S

on another note, whats the best way to edit/tweak your mesh after you have skinned it? because if i pose the model and notice something wrong in that pose and want to move the vertices, when i try to transform them, they go in the wrong direction because of the deformation, so i can only edit and unwrap the mesh in the initial bind pose, which isn't very useful.