IT'S bad-behavior time on the sets of a trio of movies now being shot.

Chris Tucker, the star whose large paycheck and ego have been well-documented, has been demanding script changes in "Rush Hour 3."

"He won't come out of his trailer until the script is up to his standards," giggled one spy on the set in Santa Ana. "What, $25 million isn't enough to just do your job and act?" A rep for Tucker didn't return calls.

On the same set, horndog director Brett Ratner "sends an assistant named Scott around to every female extra, collecting phone numbers in a too obvious, not-so-suave way," the source said. "Scott commands these $150-a-day actress-hopefuls to give him their phone numbers simply because 'the director wants it.' "

A rep for Ratner, who has dated Rebecca Gayheart and Serena Williams, said, "That's ridiculous. If Brett wants a phone number, he'll get it himself."

Meanwhile, across town, detoxing can be hard on a girl - but even harder for her co-workers. A source on the set of Lindsay Lohan's "I Know Who Killed Me" says that ever since she went to the Wonderland clinic, she's been "moody and is making everyone miserable around her. She'll be late and sometimes won't come out of her trailer." Lohan is being trailed by a "sober coach" as well as an entourage.

Lohan's hardworking rep, Leslie Sloane Zelnik, said, "I am not witnessing [cranky, moody] behavior at all. When is this girl going to get a break without everyone judging her every move?"

The third delinquent, Paris Hilton, supposedly has been late arriving on the set of "The Hottie and the Nottie," and had trouble learning her lines. "Everyone is really fed up with her right now," said our tipster.

But producer Hadeel Reda told Page Six: "Paris has never been more than 15 minutes late. Everything is memorized. She's been very professional."

Hilton has been studying with Ivana Chubbuck, one of the top acting coaches in Hollywood, Reda said. "I think people are going to be shocked at how good she is."