Los Angeles (E! Online) - Good thing she has that Ugly Betty gig to fall back on, because Lindsay Lohan's movie prospects are rapidly going the way of the dodo.

After being touted as starring in two upcoming high-profile projects—a romantic comedy with Jack Black and a drama about the Manson Family—the actress needs to line up new work after being replaced in both films weeks before shooting was to commence, E! News has learned exclusively.

And the spinmeisters are out in full force to portray everything as hunky-dory.

Alison White of producer Patriot Pictures tells E! News that Lohan is no longer a part of Black's next film Ye Olde Times, a rom-com in the world of Renaissance Faire.

But White says Lohan was not dumped. "We have just decided to go our separate ways. We currently have an offer out to another actor."

White would not say whether Lohan was being replaced for insurance, scheduling reasons or for her reputation for being difficult on set.

"That's all I know," says White.

The Black movie had been slated to begin shooting already, but is now set to start Aug. 18 in Detroit, according to White.

Lohan is also being replaced as the star of the Manson Girls, in which she was set to play Nancy Pittman, a former follower of Charles Manson. The movie will start shooting July 21 in Los Angeles.

The film's producer, Brad Wyman of Junction Films, told E! News two months ago that Lohan had signed on to star and, despite her brushes with the law and stints in rehab, there was no problem in insuring her for the movie.

Lohan's publicist tells E! News that scheduling reasons were to blame for Lohan not taking part in the films.

"She never had a contract in place [for Manson Girls] and by the time something concrete came along, Lindsay had committed to other projects."

As for Ye Olde Times, Lohan's publicist says, "Producers asked to put her on hold, but Lindsay couldn't because she was going to be busy."

Lohan's rep insists the star has a full schedule this summer already. Lohan, who recently shot a guest appearance for the Ugly Betty finale (a prelude to a multi-episode guest stint for next season), is signed on to star in Labor Pains, a new birthing comedy that will begin shooting in three weeks, and has been finishing up an album. She is currently shooting her leggings-line campaign and will be leaving next week for France to shoot a separate ad campaign.