Bakery chain Panera Bread ( PNRA) said comparable-store sales were down in May, blaming the late timing of Easter this year. Same-store sales fell 3.9% in the four weeks ended May 17. According to analysts, Easter is typically a bad sales period for Panera, since many people eat at home. In April, Panera credited a 1.9% increase in sales to the Easter shift. The drop in May sales was in line with expectations. Nevertheless, shares of Panera fell 99 cents, or 2.82%, to $34.13 on the news. Like many of the specialty food chains, Panera has a rich valuation. The stock trades at a price-to-earnings multiple of 34, using 2003 earnings estimates, compared to 18 for the S&P 500.