The biggest marquee in immediate Hollywood history is turning into a marketing nightmare for Warner Brothers.

Ocean's Twelve has suddenly been buffeted by news of stars cancelling their all-important press engagements at the last minute. The movie set for one of the year's biggest worldwide releases on December 10.

First of all, Julia Roberts, after cancelling media commitments for Closer, gave birth to twins on November 28. The fabulous news has the star celebrating, but her premature delivery has led to great worry for media execs as the superstar was one of the biggest names on the multi-starrer. Obviously, the mom of the moment can't even think about the film right now.

George Clooney, the 43-year old who plays heist ringleader Billy Ocean, has cancelled an East Coast promotional visit after spending a majority of his weekend strung up in bed in his LA house, recuperating from a ruptured disc.

The actor's representative, Stan Rosenfield, told E!Online that Clooney has had the condition for a while, but tweaked it recently, forcing him off to the doctor's. Clooney has already called off appearances on The Late Show with David Letterman set for Monday, as well as stops on Good Morning America, Live with Regis and Kelly, Charlie Rose and The Daily Show.

Rosenfield said Clooney is getting 'plenty of rest' and 'seeing doctors,' but declined to offer a timetable on the star's expected recovery.

A conspiracy-loving Hollywood is already gossiping, with words like 'intentional publicity' being tossed scandalously around.

More delicious a rumour than that, however, is the thought of a possible 'curse' on the Ocean's Twelve crew. The Steven Soderbergh film seems to be dropping stars with great alacrity, and it may be worth a look to rethink the insurance premiums on still-standing actors -- Matt Damon, Brad Pitt, and Catherine Zeta Jones!

Photograph: Getty Images