Before revision:  We show that the model is exactly solvable in the N\rightarrow \infty limit and  that the exact solution is described by a message-passing approach outlined by Karrer and Newman, generalized to include heterogeneous agents and couplings.
After revision:  We show that the model is exactly solvable in the N\rightarrow \infty limit and that the exact solution is described by the message-passing approach outlined by Karrer and Newman, generalized to include heterogeneous agents and couplings.