Two weeks after her recent hospitalization to recover from a physical and emotional breakdown, the reclusive Mariah Carey, obviously feeling better, reportedly paid a brief surprise visit to Camp Mariah in Fishkill, N.Y., a week ago. According to USA Today, the diva, 31, spent two hours at the camp last Wednesday with 150 disadvantaged youngsters from New York City, signing autographs for the campers, who each received a portable CD player and her single "Loverboy." "It was very festive," said Jenny Morgenthau, executive director of the Fresh Air Fund, which oversees five camps, including Camp Mariah. The camp is named for Carey, a Fresh Air Fund board member. "It's great that somebody that famous would come and sit and talk to them," Morgenthau said. Meanwhile, on her Web site, Carey has left an audio message for fans, assuring them of her good health and asking them to be skeptical about reports about her. Says the message: "I just want to say thank you sooo much for all the letters and everything . . . And, um, thank you, because I am taking care of myself, and as we speak -- or as I speak to you -- I'm looking at the most beautiful rainbow that is going across the entire sky, and I love you much! Thanks. Bye." As plans continue to release Carey's debut starring vehicle, the movie "Glitter" (soon after she was hospitalized on July 25, the flick's opening was pushed back from Aug. 31 to Sept. 21), her record label has managed to assemble a new video for her next single, "Never Too Far." With Carey unavailable for filming, the video will consist of existing footage from the movie, says a Virgin spokesperson. The soundtrack, Carey's first album for Virgin, is now due in stores Sept. 11.