Sony Ericsson slipped to fifth place in global mobile phone market share during the first-quarter, overtaken by Korean vendor LG. Sony Ericsson sold 22.1 million units in the quarter for a 7.5 percent market share, behind LG's total sales of 23.6 million units and 8 percent share according to Research Firm Gartner.Sony Ericsson's fall follows previous warnings from the vendor that it was experienc