Retailers posted soft sales gains in February as increased payroll taxes, delayed tax refunds and high gas prices caused consumers to trim spending. February sales at stores open at least a year rose 2% vs. a year earlier, said Ken Perkins, president of Retail Metrics. The results include drugstores. Analysts had expected a 2.5% rise. If you back out drugstores, which turned in negative same-store sales for the month, comps were up 4.3%. That was