Demand for U.S. corn appears threatened by the Chinese rejections of corn shipments containing the not yet approved MIR162 GM event. Traders fear the volume of rejections will soon escalate. General Comments Trading overnight featured lower prices and moderate volume, but it did not quite prepare the market for the avalanche of selling that dominated the day session. Nor was today's weekly export sales report a harbinger of what was coming either. Last week's corn sales were about as expected, totaling 804,800 MT of which 695,400 MT were old crop. Soybean sales reached 1.5225 MMT including 1.1086 MMT of old crop, double what the trade had expected. Wheat sales of 382,900 MT were disappointing, but, in any case, pre-report expectations for...