STAR'S LIKE WHITNEY HOUSTON, DIDDY, MARIAH CAREY & USHER HAVE ALL TURNED DOWN WENDY WILLIAMS REQUEST FOR INTERVIEWS! THEIR STILL MAD ABOUT THE THINGS SHE SAID ABOUT THEM WHEN SHE WAS ON THE RADIO!

Whitney Houston won't be sitting down for a chat on the "Wendy Williams Show" anytime soon: A source says she's still steamed about the infamous on-air confrontation she had with Williams back when the host was a radio shock jock.
Houston isn't the only one holding a grudge. In what talent bookers for the talk show are calling the "Wendy BLACK-lash," a slew of A-list African-Americans — including Mariah Carey, Usher, Tyler Perry and Diddy — have all refused to visit the show.

"Wendy isn't that far removed from her days of bashing black Hollywood's who's who on her radio show, and people have long memories," says a source close to the chatfest. "Producers are begging the biggest stars in the business to come on the show, but they're getting turned down flat."

Houston is allegedly still smarting from the 2003 radio exchange she had with Williams, in which the shock jock continually asked questions about her alleged drug problems. After several nasty exchanges, Houston proclaimed, "If this were back in the day in Newark, I'd meet you outside."

But perhaps the bigger beef belongs to Carey. After the songstress' feud with Eminem became especially ugly in July — she hit the Top 10 with a song that some say disses the rapper; he then released a track calling her a "bitch" and a "whore" — Williams came to the defense of ... Em. "Mariah, you started this," she said, before dissing Carey's husband, Nick Cannon.

Says the source: "Despite declarations from producers that 'Wendy has changed,' celebrities like Whitney and Mariah are like, 'Hell-to-the-no.'?"

Meanwhile, male stars like Diddy, Tyler Perry, LL Cool J and Usher are also turning down Williams because she questioned their masculinity on the radio, repeatedly calling them "gay."

A rep for Williams said: "Our bookers are still in conversations with reps for Tyler Perry, Whitney Houston and many others about appearing on the show."

The program could certainly benefit from some star power. Since its debut, the show has had less-than-impressive ratings, causing producers to come up with a last-ditch effort to save it: They're asking Omarosa to return. "The Apprentice" spitfire is credited for helping the show get green-lit after her now-that's-good-TV blowup with Williams during a test run in July 2008. Says the source: "They're trying to do anything to boost the ratings."