Auto parts retailer AutoZone (AZO) is retreating after the company's CEO, Bill Rhodes, said during the company's earnings conference call this morning that its sales "have remained inconsistent and below our desires and expectations." The company's sales growth during the first two weeks of February, which are the last two weeks of its second quarter, were below normal historical levels, Rhodes added. Usually the company's sales during these two weeks increase significantly compared with prior weeks, the CEO explained. This year, however, its sales rose only modestly versus previous weeks, Rhodes said. Moreover, its U.S. same-store sales during this period tumbled 8% versus the same period in 2012, he reported. The weakness was caused by delays in the processing of tax refunds by the IRS, the CEO stated, adding that the company's outlook remains "cautious." AutoZone's domestic same-store sales dropped 1.8% during its entire second quarter. On a positive note, AutoZone's second quarter earnings per share of $4.78 and revenue of $1.9B were slightly ahead of analysts' consensus estimates. In early afternoon trading, AutoZone shares fell about $5, or 1.3%, to $373.56. Meanwhile, Advance Auto Parts (AAP), one of AutoZone's competitors, dropped 1.6% to $77.10.