Discrete breathers that arise in doped alkali halides lead us to study two properties of these localized excitations. First, we note a bifurcation phenomenon, which we dub torus doubling, in which resonant coupling in the nonlinear modes induces a period doubling of the phase space structure. Second, we find that although two-frequency breather excitations are not in principle localized (because of phonon resonances), in practice they can survive 10;{9} times the characteristic time scale and give rise to marked physical phenomena, including the one that brought us to this study, the anomalous decay of luminescence.