Oof. Britney Spears is having a rough time lately. Aside from her engagement to Jason Trawick biting the dust, she nixed renewing her 'X Factor' contract in favor of a Las Vegas residency deal ... and now that's fallen through, too. And of all people, Beyonce may be to blame!

Buzzfeed reports that Caesar's has flat out denied any talks with Spears and that there's no room for the pop princess on their roster. "[Our roster is] packed every weekend," the casino's rep said. The mouthpiece did add, though, that Caesar's "is engaged with a number of today's top artists in discussions regarding headlining residencies at our venues in Las Vegas," and that they're "always interested in having artists with the caliber of Britney Spears performing at our theaters."

This goes against a whole lot of chatter that's been going for months ... sort of. Spears did have a few offers, just not Caesar's.

"There was one definite offer for Britney in Las Vegas," a Sin City source said. "A second one followed when the news broke," and it's still in "serious consideration."

However, those offers may have been rescinded recently. Apparently Beyonce's lip-syncing controversy scared a lot of bookers. Another source said that Spears lip-syncs often, and that was a sticking point in her contracts -- something we touched upon previously, but that has gained more attention since Bey's inaugural performance. A source said, "I've heard no talk about Britney since the Beyonce incident."

Still, it's Britney Spears. It's widely known that she doesn't always use live vocals, but she can still put on one helluva show, so time will tell.

Watch the Britney Spears 'Criminal' Video