AutoZone (AZO) reported a 3.1% year-over-year fall in its profit to $236.1 million or $4.43 per share for the fourth quarter of its fiscal year ended August 29, 2009. However, excluding the additional week in last year's fourth quarter results, the profit increased from $227.9 million, or $3.63 per share. The company has also managed to come close to the Zacks Consensus Estimate profit of $4.45 per share. Gross profit as a percentage of sales remained 50.3%, the same as the year-ago level. While gross margin was positively impacted through continued leverage of distribution costs due to improved efficiencies and lower fuel costs, it was offset by a shift in merchandise sales mix to lower margin products. Operating expenses as a percentage of sales increased to 31.6% from 31.4% last year. However, excluding the impact from last year's additional week, operating expenses as a percentage of ...