debut in the SBS TV series Three Leaf Clover, starring opposite Ryu Jin, Kim Jung-hwa, Kim Kang-woo, and Lee Hoon. However, the 16-episode drama received low ratings (less than 10%) and Lee was criticized for her acting, with viewers saying she was miscast as a downtrodden but cheerful steel mill worker. On August 8, 2005, she co-hosted the annual Korean Music Festival for the second year running. 2006–2007: Signing with Mnet and Dark Angel In February 2006, Lee released her follow-up album, Dark Angel. The first single, "Get Ya!", was accused of being plagiarized by the songwriters of Britney Spears' single "Do Somethin'". It was reported that Lee had signed a three-year contract with Mnet Entertainment (currently Stone Music Entertainment) for , becoming the highest-paid female singer in South Korea (approx. per year). Despite the failure of her previous drama Three Leaf Clover, in 2007, Lee starred opposite Lee Dong-gun in the mini-drama If in Love... Like Them. Although originally announced as being only one episode long, it aired for four episodes on Mnet. An edited two-episode version of the drama also ran on SBS. During filming, part of a roof Lee was standing on collapsed. Only her foot fell through, but reportedly the fall might have been fatal if co-star Lee Dong-gun had not rescued her. In February 2007, Lee announced her new digital single which would essentially be the soundtrack to If in Love... Like Them. She performed all three main tracks from the single on Inkigayo on February 25, 2007. The lead song was "Toc Toc Toc" (). Despite the single's genre being R&B, Lee began to sing more ballads afterwards, slowly moving away from her "sexy superstar" image. The single, although initially given a digital-only release, was given a limited retail release of only 30,000 copies. It was released on March 6, 2007, and in addition to the three tracks found in the digital single, it included a reworked version of "Toc Toc Toc." It was the best-selling album for that month, selling 27,845 copies. Although her single was commercially successful, her drama was heavily penalized for violating advertising guidelines, as If in Love... Like Them had several instances of overt product placement, in addition to using Lee's songs in the soundtrack. The Korean Broadcasting Committee ruled that the drama should not be aired in South Korea again, and that the network must apologize to its