  We develop a semiclassical Boltzmann-Langevin theory of the spin polarized
shot noise in a diffusive normal metal spin-valve connected by tunnel contacts
to ferromagnetic reservoirs with noncollinear magnetizations. We obtain basic
equations for correlations of the fluctuating spin-charge distribution and
current density matrices by taking into account the spin-flip processes and
precession of the spin accumulation vector in the normal metal. Applying the
developed theory to a two terminal FNF structure, we find that for a small
spin-flip strength and a substantial polarization of the terminals the shot
noise has a nonmonotonic variation with the angle between magnetization
vectors. While the shot noise is almost unchanged from the normal structure
value for parallel configuration and increases well above the normal value for
antiparallel configuration, it suppresses substantially at an intermediate
angle depending on the ratio of the conductances of the N metal and the tunnel
contacts. We also demonstrated pronounced effects of the polarization and the
spin-flip scattering on the shot noise which reveals the interplay between
relaxation and precession of the spin accumulation vector in the N metal.
