Xylem beat second-quarter estimates, but investors were not impressed.Shares of Xylem (XYL -5.69%), the water infrastructure specialist, were falling today after the company beat analyst estimates in its second-quarter earnings report, but it still wasn't enough to live up to the stock's high valuation.As a result, the stock finished the day down 5.7% on Tuesday. Xylem's results were strong but weren't enoughRevenue in the quarter jumped 26% or 9% organically, reaching $2.17 billion and topping estimates of ...