George Clooney's bare butt is causing trouble for his new movie, the sci-fi adventure Solaris.

The Motion Picture Association of America has given the Steven Soderbergh-directed flick an R rating, which prohibits the admission of anyone under age 17 who isn't accompanied by an adult.

Soderbergh, who plans to contest the restrictive rating along with the film's distributor, 20th Century Fox, blamed it on two scenes in which Clooney shows off his rear.

In one, the actor and co-star Natascha McElhone, who plays Clooney's dead wife, are shown from behind as they dance naked.

Soderbergh told the Los Angeles Times the scene was shot in a dark room "from 70 feet away."

In the other shot, "they are in bed on their stomachs, talking. Again, it's night and very dark," said the Oscar-winner.

"We've seen scenes like this on network television.''

Soderbergh said he would confront the MPAA appeals board next week.

The movie is scheduled to open Nov. 27.

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