Transfer Weights does not affect one edge loop I have a modular character with separated parts (for game) and different head variations. For some reason one head has differently weighted edge loop around neck, which causes problems when moving neck bone:

Both heads have vertices in the same place along this problematic edge loop and both are separated from torso. If Head nr 1 deforms correctly, then, after transfering weights, Head nr 2 should deform the same way, right? When i Transfer Weights from Head 1 to Head 2 it transfers the weights (i've tested it), but this problematic edge loop is still detaching when moving neck bone. How to solve this problem? Here's my .blend file ('Head2' mesh is hidden): http://www.pasteall.org/blend/35974
It may be not an exact 100% answer, but i've managed to find a workaround:
I've recreated Head nr 2 by duplicating Head nr 1 and deleting all polys besides these near edge loop. Then, from Head nr 2 i took all polygons besides these around edge loop and connected it to duplicate of Head nr 1. This way, the edgeloop remained from Head nr 1, and the rest is from Head nr 2 - which gave me a Head nr 2 without problematic edgeloop. 
Problem solved, but i still don't know why it could not transfer weights properly.