Two years after the release of Tres, Baek released her fourth album Smile in September 2003. Although not a runaway success, it managed to sell a decent number of copies, placing 46th for the year. However, her real comeback occurred in 2006, when Baek released her fifth album Smile Again in March. "사랑 안해" (I Won't Love), her first single from the album, was a ballad, unlike the rest of her Latin-style singles. Although this was a significant change, it proved to be a very popular song, getting to the top spot on certain performance show charts. This change was not a permanent one, as there were many Latin/dance tracks on the album. In fact, the second single has seen Baek going back to her musical roots, as Ez Do Dance is a sexy Latin number. She performed this single until the end of summer 2006, at which point she finished promotional activities for the album. In November 2006, Baek won Best Female Solo Singer at the MKMF Awards and was nominated for the Overseas Viewer Award.