We don't usually believe any story that connects Britney Spears and Justin Timberlake(they dated a million years ago -- he's not still crushing on her!), but this one sounds like it could be true.

It seems that Brit was supposed to record a duet with JT, but the pop tart backed out at the last minute. Britney had time scheduled to record in the studio with Timbaland, who would later mix in Justin's voice. "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," an insider tells Page Six. "It's crazy. 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."

But it's not all about business -- bigwigs at her record label, Jive, are said to be concerned for her welfare. "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," another source says. "People at Jive have been with Britney since album one, and have an investment in her. They have faith that once the material is there, she will become focused and step it up. She's very competitive, but at the end of the day, it's hard. She has to do the work -- no one can do it for her."

Poor Brit! We'd happily take Crossroads-era Britney over this new, unimproved one (and that's saying a lot).

P.S. -- OK, now Us Weekly's saying Brit and JT were never supposed to work together. Serves us right for being so gullible!