Britney Spears Backs Out of Justin Timberlake Duet

Stop the presses. You're simply not going to believe this latest piece of celebrity news.

Britney Spears is "sick" and "crazy."

We know, we know. That's not news.

But what's interesting is that in this case, such taunts are being lobbed at Spears from reputable music business insiders.

Yes, the "singer" reportedly ditched an opportunity to do a duet single with former flame - and current mogul - Justin Timberlake.

The New York Post reports that Justin wrote a song specifically for Brit, and that her label, Jive, was counting on the tune to jump start a comeback for the train wreck.

The duet, to be produced by hit-maker Timbaland at his studio in Virginia Beach, may have started a big comeback for Spears, who peaked before two marriages and two kids.

But just before she was supposed to fly out to record the song, Britney Spears - as has become her custom - reportedly "abruptly canceled the session."

Perhaps she was too busy getting her (mind) freak on with Criss Angel?

Britney Spears + Criss Angel = Spangel ? Angelears ?

A music "insider" tells the New York Post, "Everyone is worried ... People like her are sick. It's like an anorexic who's sick in the head and needs help."

Or... someone who's bonkers! Anorexia of the brain? There are actual mental problems, you know. Like depression? Come on, music "insider."

Jive is reportedly still standing behind Britney, but its execs there are "worried" about her bombing at the upcoming MTV Video Music Awards.

Reps for Justin Timberlake had no comment.