Mischa Barton might have come clean about her "full-on breakdown," but people burned in the wake of it -- namely, her former peers from The O.C. -- aren't so quick to forgive her, as she tries to revive her career.

An insider tells Breaking Celebrity News that the cast, spearheaded by Rachel Bilson, is upset with the show's former focal point because of her mercurial behavior on the set; and the tarnish they believe she left on their careers with her professional missteps.