jagged tearing polygons on iphone but not editor

I have a 3d character whose bone rotations are set using a script. In the editor if I rotate the abdomen the polygons stretch with the rotation. On the iphone the same bend makes the model look like the polygons are tearing apart --they look jagged and broken as if the model is being ripped in half.

Are there settings that control how the model polygons bend?

Thanks,

http://docs.unity3d.com/Documentation/ScriptReference/QualitySettings-blendWeights.html