  The 2.5 sigma discrepancy between theory and experiment observed in the
difference Delta ACP = ACP(B- --> pi0 K-) - ACP(Bb0 --> pi+ K-) can be
explained by a new electroweak (EW) penguin amplitude. Motivated by this
result, we have analyzed the purely isospin-violating decays B_s --> phi pi0
and B_s phi rho0, which are dominated by EW penguins. Our results extend the
analysis in arXiv:0910.2809 and have recently been published in
arXiv:1011.6319. Here we give a brief overview of the outcome.
