here's a more in-depth version of that article...
            Freddie Prinze Jr.: 'Unprofessional' Kiefer Sutherland Almost Made Me Quit Acting
                                                                                                                     By 
Kelly Woo                                 2 hours ago                                                                                                   
Yahoo TV                                                  
                 
Kiefer Sutherland and Freddie Prinze Jr. on '24: Day 8' (Fox/Everett Collection)
Most  of the time, actors gush about each other, so it's rare to hear one  slamming another, especially to the media. But that’s what happened this  weekend at San Diego Comic-Con, when Freddie Prinze Jr. openly dissed  former 
24 co-star Kiefer Sutherland. Prinze, who was promoting his animated series 
Star Wars Rebels, told 
ABC News that Sutherland was such a nightmare to work with that he "just wanted to quit the business after that."
 Prinze grew up in the industry (his father was an actor) and started  acting right out of high school. He became a teen heartthrob thanks to 
I Know What You Did Last Summer and 
She's All That before growing into heavier roles, like on 
24. Little did he know that what seemed like a plum, high-profile job would go so sour.
 "I did 
24, it was terrible. I hated every moment of it,"  Prinze said. "Kiefer was the most unprofessional dude in the world.  That's not me talking trash, I'd say it to his face, I think everyone  that's worked with him has said that."
.
Kiefer Sutherland and Shohreh Aghdashloo on '24' (Fox)
Well,  not everyone has said it publicly, but there have been rumblings about  Sutherland's difficult behavior on set. Oscar nominee Shohreh  Aghdashloo, who joined the cast in Season 4, 
believes her character was killed off unexpectedly because she clashed with Sutherland. "I'm afraid working with him proved to be hard. That young man was pretty angry," she told 
Fox & Friends.
 Prinze’s problems with him apparently stemmed, in some part, from  their height difference. After 24, he worked as a producer and director  for WWE’s Vince McMahon.
 "At least he was cool and tall. I didn't have to take my shoes off to  do scenes with him, which they made me do," Prinze said. "Just put the  guy on an apple box or don't hire me next time. You know I'm 6 feet and  he's 5'4."
 Yahoo TV reached out to Sutherland's reps for comment, but have yet to get a response. (Also, according to most 
reports, Sutherland is described as 5-foot-9.)
 Not all of Sutherland’s co-stars think he’s difficult. On 
The Late Late Show in 2002, Elisha Cuthbert (who played Jack Bauer’s daughter on 
24) said the actor was serious, but professional. And young David Mazouz, who played Sutherland’s son on 
Touch, 
raved about how “patient and kind” he was.
 
Kiefer Sutherland and Mary Lynn Rajskub in '24: Live Another Day' (Fox)
But it’s very telling to hear what Mary Lynn Rajskub, who starred as Chloe O'Brian on 
24 for seven years, has said about the actor. On Marc Maron’s podcast, the actress was diplomatic, but 
gave indications that his reputation might be true. "Kiefer and I like each other; I  would go so far as to say we love each other in that respect," she  said. But then, she added that they'd never really developed a personal  relationship — despite working together for seven years (plus the time  from 
24: Live Another Day). 
 Much of the cast and crew became  like a family, she noted, "But we never fully hung out or fully had a  conversation the entire time."
Update: some responses from people involved in the production.
 
24‘s dialogue consultant Marci Michelle (and close friend of Kiefer) called Freddie a “jackass” on Twitter and said “Ahhh, love it when actors are promoting a new gig by bashing their last gig. Pathetic.” 
 Scott Meslow tweeted “I PAed on 24, and Kiefer Sutherland was a hell of a lot more professional than Freddie Prinze Jr.” and followed it up with “It’s less a legitimate gripe and more a basic misunderstanding about how leading actors are shot in pretty much everything.”