NEW YORK ( TheStreet) -- Early this week CoreLogic ( CLGX), the firm that tracks mortgage debt, reported some cheery news about rising home prices. But on Thursday the firm added a reality check: More than a fifth of homeowners with mortgages remain underwater, and this bad situation is unlikely to change very fast. It is improving, though. During the third quarter of 2012, about 100,000 borrowers moved into the black from a state of negative equity, or owing more than their homes were worth. The main reason was rising home prices. During the 12 months through September, some 1.4 million borrowers moved from negative to positive equity, but 10.7 million borrowers, or 22% of homeowners with mortgages, remained underwater. That's down from about 25% at the peak of the financial crisis. As of September, the total value of homes underwater was $658 billion, CoreLogic reported. "There has been steady progress relative to reducing negative equity and its effects in 2012, but with nearly one-quarter of borrowers still underwater, we have a long way to go," Anand Nallathambi, president and CEO of CoreLogic, said in releasing the report. "As we look ahead into 2013, we expect to continue to see more borrowers escape the negative equity trap, which will be a strong positive for the housing market specifically and the broader economy generally." Underwater homes are a drag on the housing market and economy because their owners are trapped. Unable to sell for enough to pay off their current mortgage, owners cannot move for a better job, take out a new loan or trade up. Ironically, though, CoreLogic says underwater homes, because they can' t be easily sold, reduce the supply of homes for sale, helping to push prices up. The problem is concentrated among low-cost homes and in the states hit especially hard by the housing crisis. Together, Nevada, Florida, Arizona, Georgia and Michigan account for 34% of the negative equity in the country. The 6.6 million underwater homeowners who have first mortgages but no home equity loans account for about $323 billion in in negative equity. Their average mortgage balance was $214,000, putting them underwater by $49,000. Among the 4.1 million underwater borrowers who had home equity loans as well as mortgages, the negative equity totaled $334 billion. Their average mortgage balance was $298,000, and they were underwater by $82,000. The large negative-equity figures mean it could take years for those borrowers to get to a state of positive equity, when the home can be sold for enough to pay off the loan. A homeowner reaches this state as the home grows in value and monthly payments gradually reduce the debt. A homeowner can speed the process by making extra principal payments, or with do-it-yourself improvements that add more value than they cost. Use this calculator to examine your own situation.