James Franco found out why the producer of his next film, "Spring Breakers," has been banned from "The Late Show" with David Letterman since 1999.

On Monday, Franco was a guest on "The Late Show" and Franco vouched for Harmony Korine, who Letterman said allegedly found Korine snooping through Meryl Steep's purse 14 years ago.

Franco told Letterman that the filmmaker is a "great person to with, but I think he had a period where he was going a little off the rails." He added that, "the legend is that he pushed Meryl Streep backstage. I mean if you push Meryl Streep backstage you get kicked off. But he said he was a little out of it, so maybe he was on something that night."

During the appearance in 1999, Korine's film "Julien Donkey-Boy" was released.

"I went upstairs to (the green room to) greet Meryl Streep and say welcome to the show, and I looked around, and she was not in there, and I found your friend, Harmony, going through her purse," Letterman told Franco. "True story. And so I said, 'That's it, put her things back in her bag and then get out of here.'"

Korine gained notoriety for the film "Kids" that he wrote in 1995. The film was based on when HIV was booming and followed sexually active teenagers in New York City.

"He didn't tell me that, but he's a good guy now you should bring him back on. I vouch for him," Franco responded to Letterman's story.

Letterman resolved a 16-year-feud with Oprah when Letterman said he and his girlfriend skipped out on a bill for a meal in 1989 with Oprah. He said he tricked the waiter into thinking Oprah paid for it, according to News.com.

The public feud finally ended with Oprah was a guest on "The Late Show" in 2005.

Korine would have to wait three more years to reach 16 years as a banned guest on the talk show.