might be inconsistent with the compact orbital architecture of the giant planets invoked by the LHB model.

-   Jupiter –and to some lesser extent Saturn–, being a giant planet, undergoes type II migration. It is well known that this kind of migration follows the global evolution of the disk. The numerical algorithm used in MS01 could not model the evolution of the disk correctly, as it considered only an annulus of it, with wise –but nevertheless arbitrarily chosen– boundary conditions. In Crida et al. (2007) we have presented a new hybrid scheme that allows the computation of the global evolution of the disk, using a system of nested 1D and 2D grids. Consequently, this algorithm allows a correct simulation of Type II migration. It is true that MS01 argues that, once the planets are in the 2:3 resonance, they are no longer locked in the evolution of the disk (the reason for which they can move outward, despite the disk has a global motion towards the Sun). Nevertheless, the torque unbalance that MS01 measured depends critically on the mass of the disk inside the orbit of Jupiter, and the latter depends on the global evolution of the disk. In particular, 