I’m not entirely sure but I think this started in Unity 3.5. The orientation of my bones seems to lag behind the mesh animation. What this means for me is that attached objects on my characters will bob around as if they are being dragged behind the animation.
Normally this wrist attachment would be joined to the player’s wrist, but it’s offset quite a bit since the arms move about quite a bit while running. This behavior is consistent with other attachments such as the glasses (which clip a little in this screenshot), and the hair.
I’ve tried forcing the attachments to have a zeroed out transform on every LateUpdate thinking that something funky was going on but no joy. I’ve watched the bones and they don’t seem to be doing anything strange with their transforms and the attachments transforms are always at zero local position/rotation.
Also, I tried to send a bug to Unity but the bug reporter threw an error.