Stability against flute modes. localized inside the plasma column, of magnetic confinement configurations which are relevant for the realization of poloidal divertors, is studied for a bell-shaped current-density profile. The ideal MHD-equilibrium is described by using the Herrnegger-Maschke solutions of the equilibrium equations. It is shown that there is little difference between the stability conditions for toroidal diffuse pinches with the shape of the cross-section resembling a normal or inverted D, and that these two shapes of the plasma cross-section are preferable to a rectangular one if the plasma column is very elongated in the vertical direction. A comparison is made with the results based upon a flat-current-density equilibrium model.