Missing: Mischa Barton partied in Cannes but did not attend the premiere of her new movie

Mischa, 22, pulled out of any promotional work because she was apparently going home.

But according to my source, Mischa thought the film was awful and didn't want to be involved in the project.

And I'm told that the OC star was still on the Riviera, quaffing champagne while her film premiered.

When asked why she wasn't at the premiere, Mischa snapped: "I was never due to go." So, why were you in Cannes, Mischa?

The Roland Joffe directed affair sees the Mischa playing one of two teenage girls who fall in love after they meet on the fansite of Russian girl group t.A.T.u. and then at a concert in Moscow.

The plotline describes how they "are swept into a dangerous world of obsession, drug abuse and murder".

Bandmembers Lena and Yulia, not surprisingly, play themselves in the film, which is set in Moscow and LA.

Barton - who played television beauty Marissa Cooper in The O.C. - has been charged with possession of marijuana, driving under the influence, driving without a licence and driving with a blood alcohol level above the legal limit.

The charges made following the actress' December 27 arrest.

According to the police report at the time, Barton was pulled over in West Hollywood, California, when police saw her driving in the middle of two lanes and failing to signal when making a turn.

The star spent about seven hours in jail on the night of her arrest and was later released on $10,000 bail.

Barton accepted her responsibility for the arrest on American Idol host Ryan Seacrest's radio show after her release.

She said: "I don't know what to say about it except I'm not perfect."