Envelope Operator funkyness

[Sergio Mucino]

I'm seeing something a little bit odd, and I was wondering if it was normal, or if someone else had seen it before. I've got a quite complex mesh that I'm enveloping to a set of nulls. Everything is ok. I then do a Smooth Envelope Weights on the mesh, and then maybe tweak some weights using the Edit Weights table. Once I'm done, if I take the Envelope operator and mute it/unmute it, I can see the verts of the mesh shift positions. Sometimes (on other meshes) its by a super tiny bit. Other times (as in this mesh) it is more noticeable. I was wondering why this would be. Am I doing something that somehow disturbs the "rest shape" of the mesh stored by the operator (if it is that way how it works)? Can this cause problems down the road? Can it be prevented? Thanks for any comments! --