JA Solar (NASDAQ:JASO) drops 14.3% premarket after reporting Q2 revenue of $413M (+12% Y/Y) and EPS of -$0.22, missing consensus by $5.6M and $0.19. Gross margin fell to -2.7%. The company is lowering its 2011 shipment forecast to 1.8GW from a prior 2.2GW. Like other solar names, JA Solar blames European weakness for its poor results.