  Deviations from Fermi liquid behavior are well documented in the normal state
of the cuprate superconductors, and some of these differences are possibly
related to pre-formed pairs appearing at temperatures above T_c. In order to
test these ideas we have investigated the attractive Hubbard model within a
self-consistent, conserving ladder approximation. In this version of the
theory, no feature is present which can be related to the pseudo gap found in
the high-T_c materials. Further, the interactions between two-particle bound
states change the physics of the superconducting instability in a profound
fashion, and lead to a completely different phenomenology that one predicts
based on the non-self-consistent version of the same theory.
