Fannie Mae has made improvements to its Desktop Originator/Desktop Underwriter automated systems aimed at helping first-time, underserved and minority homebuyers and boosting lender and broker business. The DO/DU enhancements will take effect for loan applications run through DO/DU on or after July 24. Fannie Mae representatives said the underwriting changes cover new 40-year term mortgages and MyCommunityMortgage loans. The DU changes also reflect a new collection payoff policy, updated condominium project guidelines, and new