(Image source: retailindustry.about.com) Shares of the Gap Inc. (NYSE:GPS) are down in current trading after the retailer revealed a 6 percent drop in comparable store sales for the month of March. In addition, shares were also downgraded to neutral from buy by Janney Capital Markets. Janney Capital Market cited expanding inventory over sales and continuing upward cost of promotion as reasons for the downgrade. Despite the plunge in comparable store sales, Gap reaffirmed its full year earnings outlook.