The second quarter national average for single-family home prices increased 3.6 percent to $177,000 over the year-ago quarter, according to the Fiserv Case-Shiller Indexes.

The rise was driven by strong price increases in relatively high-priced markets, such as San Diego, Washington, D.C., and the San Francisco Bay Area, according to a statement. Even though the national average rose, prices fell in 70 percent of the 384 metro areas surveyed by Fiserv Case-Shiller, with many experiencing double-digit drops.

Chronic high unemployment, the expiration of the homebuyer tax credit and the large number of distressed properties were factors that affected the housing market, according to a statement.

"Some of the largest declines in prices will occur in markets that had strong spring and summer 2010 price increases," said David Stiff, chief economist at Fiserv. "This is because the homebuyer tax credit delayed the correction in home prices that is necessary to return housing affordability to its pre-bubble levels."

Fiserv Case-Shiller expects that the second double-dip declines will continue through the rest of this year until the end of next summer, according to a statement.

"Many of the metro areas that were fortunate enough to have a spring and summer bounce will experience double-dip price declines," said Stiff. "If there are no downside surprises for the economy or the housing and mortgage markets, home prices should start to stabilize at the end of 2011."