Mootools

Take this vertex for example:


If I move the vertex:


Is there any option I should tick in the Polygon Cruncher to prevent this from happening?

Strange result, which should not occurs.

I guess that there might be an UV seams along the line that belong to the vertex.
Cruncher might move points along that line independently on both side of the frontiers.
I suppose this lead to such results.

Having the mesh would help to understand why this occurs.
This should be dig.

Thanks,
Manuel