Jessica Simpson's latest movie is reportedly so bad her manager father has delayed its release date.'Blond Ambition' - based on hit 80s film 'Working Girl' and co-starring Luke Wilson - has had its release date changed several times amid fears it will be a huge flop. A source told the New York Daily News newspaper: "The release date, which was set for August 3, has now been delayed until the last week of August. Jessica's father Joe then intervened and said he wasn't comfortable with the level of competition from other films that month."Another source adds: "Jessica was not very focused on set and flubbed her lines often. She always had her dog around, was on the phone with her then-boyfriend John Mayer or was sitting in a warmed-up SUV."The film is still said to be incomplete and does not yet have a firm release date. Had it been released in August as intended, 'Blond Ambition' would have gone up against 'The Bourne Ultimatum' and 'Rush Hour 3' at the box office. Meanwhile, Jessica is reportedly set to go on a date with Hollywood star Jake Gyllenhaal, with rumors rife the pair have a crush on each other.