bugg in update methode of xPhysSurfCut
When close node treatment involve several element all null iso-edge points to the close node for upper "creator". Then close node points to one of those elements.
When updating an iso that rotate around this close node treatment the cleanAroundEdge if called with one edge not anymore cut, will destroy this last link. And if among the remaining element one is not topologicaly new there will be a problem as this link from close node points to one of those elements is broken and not re-created. It is a bug.
It has been discovered by B.L. with iso that move slowly.