"Timbaland 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 the session and refused to do the song.
"It's crazy," the insider added. "She's looking for a comeback, and this would have not only been a huge hit, but something she could have opened the MTV Video Awards with and really blown everyone away."
Another insider said, "Listen, everyone is worried. In her mind, her album is done and she's done enough work . . . She's an easy target right now, because she's . . . sick. People like her are sick. It's like an anorexic who's sick in the head and needs help. She needs help. It's sad because what she's got – and we've heard it's like bipolar disorder – can easily be treated with medication, but she won't do it."
