The number of Americans initially applying for unemployment aid swung back last week as technical problems that pushed the figure down to a seven-year low in the previous week had been partly worked through, the U.S. Labor Department reported Thursday. In the week ending Sept. 14, the advance figure of seasonally adjusted initial claims for jobless benefits rose by 15,000 to 309,000 from the previous week\'s revised figure of 294,000, the lowest level since April 2006. Computer-system update in California and Nevada delayed the processing of applications half a month ago, which may still distort data in the coming weeks. Outside of the irregularities two weeks ago, the fresh reading for last week was the lowest since September 2007. The four-week moving average, which helps smooth out week-to-week volatility, declined by 7,000 to 314,750, the fewest since October 2007, and stayed well below the benchmark level of 375,000, which indicates a sustained recovery in employment. The advance figure of seasonally adjusted insured unemployment during the week ending Sept. 7 stood at 2.787 million, down 28,000 from the previous week. The U.S. unemployment rate edged down to 7.3 percent in August, the lowest since December 2008, and the economy added 169,000 jobs in the month.