(For more real estate news, see DQNews.com.)LA JOLLA, Calif. -- Southern California home sales shot up by an unprecedented 65% last month from the dismal, record lows of a year ago, when a credit crunch slammed the brakes on home financing. September sales also posted a rare gain over August as price cuts lured more buyers. Foreclosure resales rose to half of all transactions. A total of 20,497 new and resale houses and condos closed escrow in the six-county Southland in September, up 5.8 percent from 19,366 in August and up 64.6% from 12,455 in September 2007, according to San Diego-based MDA DataQuick, a real estate information service. Last month's sales were the highest for any month since December 2006 and the year-over-year gain was the highest for any month in DataQuick's statistics, which go back to 1988. However, last month's sales were still the second lowest for any September since 1996 and were 17% below the 20-year sales average for that month. This September's huge annual sales increase stems from the extraordinarily weak activity in September 2007, when sales were at a record low for that month. The year-ago sales plunged after the credit crunch that struck in August 2007 made "jumbo" mortgages for higher-end homes more expensive and harder to obtain. Sales were already hurting from the subprime mortgage industry meltdown earlier in 2007, which undermined demand for entry-level homes. "The pitifully low September 2007 sales numbers weren't tough to beat. More impressive was that this September's sales volume bucked the seasonal norm and rose above August. Steep price declines, especially inland, have improved housing affordability quite a bit and may keep sales levels well above the record lows we saw late last year and early this year. It will depend on the severity of this economic downturn," said John Walsh, MDA DataQuick president.