A new report from market research firm IDC says that sales of the Iphone fell 10% in the most recent quarter, and its almost entirely due to falling popularity in China. Apple sold 50 million Iphones from January through March, compared to 55 million in the same period a year ago. In the full smartphone market, IDC says total sales increased 7.8% year on year, and with 21% of the global market, Samsung is once again the largest manufacturer.