Zacks says that the Berkshire-Hathaway first quarter 2011 operating earnings report shows a 49 percent drop from Q1 2010.  Although total revenue gained 5.3 percent year-over-year, net income was .61 cents per share, dropping 59 percent from the same quarter last year.  The loss was attributable primarily to insurance expenses following earthquakes in Japan and New Zealand, and floods and a cyclone in Australia.  In its financial products division, revenues declined 6.6 percent overall to $913 million, with a revenue loss of 12.4 percent in Clayton Homes due to the continuing surplus of single family homes on the market.