  We reconsider the problem of the superconducting proximity effect in a
diffusive ferromagnet bounded by tunneling interfaces, using spin-dependent
boundary conditions. This introduces for each interface a phase-shifting
conductance Gphi which results from the spin dependence of the phase shifts
acquired by the electrons upon scattering on the interface. We show that Gphi
strongly affects the density of states and supercurrents predicted for
superconducting/ferromagnetic hybrid circuits. We show the relevance of this
effect by identifying clear signatures of Gphi in the data of T. Kontos et al
[Phys. Rev. Lett. 86, 304 (2001), ibid. 89, 137007 (2002)].
