Vivica A. Fox, Steve Guttenberg, Ryan Sypek and “Saturday Night Live” veteran Cheri Oteri have been cast opposite Jessica Simpson in the comedy Major Movie Star for Nu Image/Millennium Films. “High School Musical’s” Olesya Rulin, “Gilmore Girls” regular Keiko Agena, Jill Marie Jones, Aimee Garcia and Gary Grubbs also star in the story of Megan (Simpson), a somewhat clueless movie star who impulsively enlists in the U.S. Army Reserve after discovering her boyfriend is gay and her cousin/accountant has stolen all her money.

Fox will play Sgt. Louisa Morley, an intimidating training officer who goes hard on Megan. Guttenberg will play the controlling agent Sidney Green, furious at her for enlisting and at Gen. Greer (Grubbs) for keeping her there. Sypek will play the handsome officer Megan falls for, Sgt. Mills Evans. Oteri will play Pvt. Jeter, the most gung-ho recruit on the base and Megan’s arch-nemesis. Jones, Rulin, Agena and Garcia will play Megan’s fellow reservists.

Filming on director Steve Miner’s feature began Monday at Camp Minden near Shreveport, La. Oteri contributed recent revisions to April Blair and Holly Sorensen’s screenplay.

The producers are Bill Gerber, Joe Simpson, Randall Emmett and Denise Di Novi. The executive producers are Avi Lerner, Michael P. Flannigan, Danny Dimbort, Trevor Short, Boaz Davidson, John Thompson and Joe Gatta. Stephen Emery and Dal Walton are co-producing.

Jessica Simpson reportedly had to abandon her birthday plans on Tuesday after the paparazzi descended. To celebrate her 27th birthday, Jessica had lunch with five friends at the Silver Spoon Beach house in Malibu and following in Lindsay Lohan’s footsteps from last week, planned to throw a barbecue in the evening for more family and friends - but soon the beach outside the property was swarming with photographers.

A source close to Jessica told People magazine that they abandoned the beach house and relocated to her parents’ house instead: “It was a private party and they wanted to keep it private.” “She was there with all of her closest friends and family. She had a great time. It was great night.”

But her celebrations couldn’t go on until too late into the night - she had to be up early to travel to an Army boot camp in Louisiana to prepare for her new film Major Movie Star. A source revealed: “She left for Shreveport. She’s going to be in boot camp for two days to learn how to do Army drills and salute properly and that sort of thing.”