May 8, 2013, 9:46 a.m. EDT U.S. stocks ease after record-setting run By Polya Lesova and Matt Andrejczak, MarketWatchNEW YORK (MarketWatch) — U.S. stocks drifted lower at the open Wednesday as investors took a break after a string of record-setting gains.The Dow Jones Industrial Average (DJI:DJIA)  fell 31 points to 15,025 after closing above 15,000 for the first time on…