Top mortgage lenders continued to face a huge backlog of pending loan buyback demands and insurance claims denials at the midway point in 2011, according to a new analysis by Inside Mortgage Trends.Five major lenders that report detailed data on repurchase exposure had a combined $19.26 billion of mortgage repurchase claims outstanding at the end of June. The good news is that figure was down 6.1 percent from the first quarter.The so-so news was that three of the companies reported increases in their repurchase claims outstanding during the second quarter. Bank of America – which had 60.1 percent of ... [contains one data chart]