Britney Back with Justin? She Just Won't Duet

Britney Spears bailed at the last minute on mixing a duet with red-hot former flame Justin Timberlake, robbing herself of a showstopping opener for the upcoming VMAs. Timbaland, who was producing the unlikely duet, "set aside a week out of his crazy schedule to do this and then, just before she was supposed to fly out, Britney abruptly canceled," a source tells the New York Post's Page Six. "It's crazy. She's looking for a comeback, and this would have not only been a huge hit, but something [that would have] really blown everyone away."Just how crazy is Brit? (Alleged hookups with Criss Angel aside?) "She needs help," another source tells the Post. "It's sad because what she's got — we've heard it's like bipolar disorder — can easily be treated with medication, but she won't do it."