Holding that arguments raised for the first time to the district court reviewing a magistrate's report were waived explaining that the "Magistrates Act was [not] intended to give litigants an opportunity to run one version of their case past the magistrate, then another past the district court"
Holding that a district court's refusal to hear a new argument not presented to the Magistrate Judge is "entirely appropriate" because "[w]e do not believe that the Magistrates Act was intended to give litigants an opportunity to run one version of their case past the magistrate, then another past the district court"