In March 2006, SM Entertainment began to recruit new members for the next Super Junior generation. However, plans changed and the company declared a halt in forming future Super Junior generations. Following the addition of thirteenth member, Kyuhyun, the group dropped the suffix "05" and became officially credited as Super Junior. The re-polished group's first CD single "U" was released on June 7, 2006, which was their most successful single until the release of "Sorry, Sorry" in March 2009. In the fall of 2007, the group released their second official album, "Don't Don", which became Super Junior's best-selling album and Korea's second best-selling album of the year.