BUENOS AIRES (AP).- There were no buyers Sunday at the auction of a 1940s stag film that an events promoter claims shows a young Marilyn Monroe having sex before she became a movie star. The auction was a flop. Nobody came forward willing to pay Mikel Barsa’s starting price of 2 million Argentine pesos, about $480,000. Barsa said it didn’t help matters that a spokeswoman for Monroe’s estate was quoted in an Associated Press interview calling the whole thing a fraud. “It doesn’t surprise me. The latest statements of Nancy Carlson didn’t do anything good for all this,” Barsa said, referring to the spokeswoman for a company in charge of protecting Monroe’s image and estate. Barsa said he was still negotiating with an unidentified buyer from Denver whom he said was offering much less than a fair price. But he also