We point out an error in recent work by Pao, Wu, and Yip [Phys. Rev.B {\bf
73}, 132506 (2006)], that stems from their use of a necessary but not
sufficient condition [positive compressibility (magnetic susceptibility) and
superfluid stiffness] for the stability of the ground state of a polarized
Fermi gas. As a result, for a range of detunings their proposed ground-state
solution is a local maximum rather than a minimum of the ground state energy,
which thereby invalidates their proposed phase diagram for resonantly
interacting fermions under an imposed population difference.Comment: 4 pages, 2 figures. Version in PR
