Head/Neck Rigging Problem I'm having difficulty fixing a problem with the head/neck bones on a character I'm working on. I modified the character "Elaine" (a .blend that I downloaded from BlendSwap)

Elaine.blend: http://www.pasteall.org/blend/32132

in order to create a new character "Maria":

Maria.blend: http://www.pasteall.org/blend/32133

In the process of making my modifications, I accidentally deleted the "head" bone in Maria's rig (unfortunately, I didn't realize I'd deleted it right away). By carefully inspecting the two rigs, I recreated the head bone in Maria's rig, and parented the bones as they are in the Elaine rig.

The repaired rig almost works. When I rotate the head bone around the global x-axis, the head moves in the same way as in the Elaine rig. However, when I rotate the bone around the global z-axis, her head doesn't rotate horizontally, instead it just twists.

Here is the correct behaviour (with the head bone highlighted):

Elaine with head bone highlighted http://www.pasteall.org/pic/show.php?id=78534

And here is the problematic behaviour:

Maria with head bone highlighted http://www.pasteall.org/pic/show.php?id=78535

Is it possible for me to fix this rig or do I need to start over? I would greatly appreciate any rig-debugging tips other users could offer.
You have a broken constraint on the bone named : DEF_head (in the last bone layer of the armature). 



Just select the bone named "head" in the "copy rotation" constraint.