This was expected, the Case-Shiller Index is actually a three month moving average. So it's June, July, and August housing data and is just barely out of the effects of the spring tax credit.
Read it allThe S&P/Case Shiller composite index of 20 metropolitan areas declined 0.3 percent in August from July on a seasonally adjusted basis. A Reuters poll of economists forecast a drop of 0.2 percent. The dip followed a seasonally adjusted decline of 0.2 percent in July.