We knew Sony Ericsson's supplies were tight following the recent natural disasters in Japan, but in retrospect it's clear the phone maker was already having a rough quarter. The company released its Q1 earnings today, and reported that its profit fell 48 percent to €11 million ($15.8 million) due to weak sales -- a shortfall compounded by higher taxes and quake-related supply constraints. To be fair, at this time last year, the company earned money after a sweet tax benefit, so its profit wasn't completely built on strong sales. All told, it sold 8.1 million phones in the most recent quarter -- down 23 percent from the same period a year ago, though the average selling price for handsets ticked up 5 percent. In particular, smartphones accounted for 60 percent of the company's sales, though by the company's own estimate, it's only snagged 5 percent of global market share. And, it seems, Sony Ericsson's management team isn't getting too ambitious -- it forecast just a "modest" uptick in overall phone sales in 2011.