When things go as seriously wrong as they do in the Sandra Bullock comedy "All About Steve," a viewer is challenged to guess what the filmmakers thought they were doing. A 1930s screwball comedy with a modern sensibility? A misguided valentine to those who march to the beat of a different drummer?

Normally, Bullock's name above the title would guarantee a decent boxoffice tally. But, here, reviews and word-of-mouth should be poisonous enough to counter that advantage.

What might have happened is that early in the shoot, the cast lost all confidence in Kim Barker's woeful script and began overselling every line. Certainly neophyte feature director Phil Traill did nothing to correct all the bad acting.

Bullock has produced her own comedy vehicles before without miscalculating this badly. So what was she thinking when she decided to play Mary Magdalene Horowitz -- yes, the woman is Jewish-Catholic -- a writer of crossword puzzles whose motor mouth drives everyone other than her forgiving parents to near suicide?

Mary spews out mysterious words and arcane facts with a nervous energy that suggests a mental disorder. She wears bright red go-go boots along with clothes, accruements and bedroom posters -- she lives with her parents -- that belong to a much less fashionable era.

Then there's her erratic behavior. One a first date, she literally jumps the guy. At another point, she actually thanks a truck driver for not raping her. Upon seeing a lethal twister in the desert, her response is to open an umbrella.

Consequently, when people encounter Mary, everyone starts edging away almost immediately. A bus driver tricks her into getting off the bus so it can continue on without her. Everyone aboard cheers. When she meets Mr. Right in the pleasing form of "The Hangover's" Bradley Cooper, he can't imagine she is anything other than a stalker.

This is a character Bullock wanted to play?

Her fleeing guy, Steve (Cooper), is a cable-news cameraman. He accompanies Thomas Haden Church's pompous news reporter -- in a performance that is all cliches -- and field producer Ken Jeong (in the film's only restrained performance) to various hostage crises and natural disasters all over the western U.S. Mary, having been fired from her crossword-puzzle job in Sacramento, Calif., relentlessly pursues Steve to every breaking-news story.

Along the way, Mary and the news crew encounter characters who are eccentric but with nothing going on beneath the surface. Situations strain for laughs, with a stunt horse getting perhaps the biggest one. Not big, mind you, just the biggest in a movie filled with unfunny humans.

The film should be on airlines in two months and off everyone's resume within three. No animals including the horse were injured making the film, so "Steve" counts as no great crime. Bit it does leave one question: Why did anybody think an attractive female star should wear red boots in every scene of a movie?

Opens: Friday, Sept. 4 (Fox)