We knew those extensions Britney Spears sported during her super-craptacular dance number Sunday looked especially cheap.

According to Norm Clarke’s Vegas Confidential:

… she wore extensions from Jessica Simpson’s Hair-u-Wear line, Vegas Confidential has learned.

Backstage spies say Spears pitched a fit. She had arranged for her own hair stylist to make the trip for $10,000 and “she wanted to go brown, but her people said ‘no way,’” said a backstage source.

Oh, the famous Ken Paves/Jessica Simpson Hair-u-Wear line. Allowing trashy mallrats across this great land to emulate their coked-out, suspended-license-defying idols.

Really, who needs a stylist when you have a mass-market line of Barbie hair at your disposal?

You can always cover up the bad patches with a well-placed c.z.-laden hand. Just like the stars!

Britney Spears needs better handlers and better excuse makers. But, we all knew that.

The lame blame game that swirled yesterday is being countered with details of Britney’s bad behavior before the awards show.

She arrived in Vegas hours after a scheduled rehearsal, was partying when she should have been working, and wouldn’t listen to the pros putting on the show.

And then came the thud of a performance seen around the world.

Page Six is reporting:

"The dance number was spectacular - without her," said our spy at rehearsal. "When the stand-in was rehearsing with the dancers, in the hours they were all waiting for her, it was amazing.

Then Britney showed up and refused to do anything. The dancers were supposed to lift and twirl her in the air a few times, and that just wasn’t going to happen. The more complicated dance moves had to be erased because she couldn’t do them."

Oh…but there’s more.

That unflattering costume? It was worn at Britney’s insistence because she thought it was "sexier" than what the professional were recommending.

Meanwhile, Spears was agitated because she didn’t like the outfit MTV had selected for her.

"MTV wanted her to wear a corset outfit. It would have looked great and covered a lot of things up, but she hated it and didn’t think it was sexy enough."

Wow.

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The Internets are ablaze this morning with theories explaining Britney’s wooden performance last night.

Photographic evidence of a glittering broken heel is being touted as the reason Brit appeared to stiffly walk through the number, barely moving her hips.

X17 is reporting that Britney Spears was suffering an impediment of a more emotional nature:

A source tells X17 Brit found out about Sarah Silverman’s crappy line about Britney’s babies just moments before she took the stage to perform "Gimme More."

Needless to say, Britney was PISSED! … as any mom would be. Britney was so upset she walked through her performance just to get it over with (despite encouragement from her friends, including Sam who was apparently yelling at Sarah backstage) to skip out on it all together).

She held up her end of the bargain and got a major slap in the face from Sarah.

We’re sure other excuses for Brit-Brit’s uncomfortable-looking routine will continue to pop up today.

We’d like to float our own theory that Britney had her Cheetos power snack way too close to curtain call.

You simply cannot shake your money maker with real feeling when you’re still digesting such cheese-flavored goodness.

Even if you do somehow get the orange stains off your hands in time.