National home prices fell for the second-straight month in September after rising, albeit slightly in some cases, in the first six months of 2010, according to the CoreLogic (CLGX) home price index. The data analytics company said its HPI fell 2.8% in September from a year earlier, following a revised drop of  1.1% in August. Excluding sales of distressed properties, home prices decreased 0.73% from the year-ago September. “We’re continuing to see price declines across the board with all but seven states seeing a decrease in home prices,” said Mark Fleming, chief economist for CoreLogic. “This continued and widespread decline will put further pressure on negative equity and stall the housing recovery.” CoreLogic said its HPI is now down more than 29% since peaking in April 2006. Excluding distressed sales, home prices are down nearly 20% over that time. The five hardest-hit states in September include Idaho, which saw prices drop 14%, Alabama 9%, Mississippi 8.3%, Florida 7.7%, and New Mexico 7.5%. (Click on chart to expand.) Five states experienced increases of less than 1% in home prices for September: Maine 0.38%, Alaska 0.44%, Virginia 0.77%, Nebraska 0.78% and California 0.86%. North Dakota at 1.73% and New York at 2.67% saw the largest home-price gains of the month, according to CoreLogic. Earlier this week, Standard & Poor’s said home prices will drop between 7% and 10% through 2011, erasing any improvements prices have recently made. And Fiserv, a financial services technology provider, said it expects a 7.1% drop over the next 12 months with some markets falling into a double-dip. Write to Jason Philyaw.