Who's the Diva on Iron Man 2?

Surprising behavior from a supposed emotionally rehabbed star on the super sequel

It's so typical: A star has a big comeback after some emotionally and quasi-notorious behavior, the public reaffirms their love for said celebrity and then they pull the diva card all over again!

And it's so what went down on the set of one of our fave bitchin' summer hits-to-be, Iron Man 2.

So, who could it be?

Is icy Gwyneth Paltrow pestering the catering department for precise cooking requirements on her free-range-only chickens?

Or maybe it's ScarJo, still trying to keep her relationship with hunky hubby Ryan Reynolds secret by requiring closed-sets only when he visits?

And don't even get us started on how many possibilities reformed-again bad boy Robert Downey Jr. conjures up...

But all these guesses are totally wrong! The real culprit is that back-from-the-brink acting genius Mickey Rourke, who, according to several I.M. on-set sources, was "such the pain."

Say it ain't so!

We totally loved the hell-raiser in The Wrestler, and we were so impressed by his professional comeback—like a lotta folks were. So why is the guy who was given such a second chance acting like his poop doesn't stink?

"I cannot tell you everything," piped our I.M. insider, "without revealing who it was who saw each incident, but I can tell you this: He was not exactly liked."

Another source on Iron Man 2 confirmed Mr. R was a bit "full of himself" and demanded that warm-up music always be played for his scenes, specifically Amy Winehouse and Gnarls Barkley songs.

"You could always tell when Mickey was arriving to the set," dished the set ear and eyewitness, "because you'd hear him coming in on his golf cart before you'd see him. It was obnoxious."

A rep for Rourke did not comment.

But hey, at least Mickey wasn't requesting Mariah Carey songs. Count your blessings, folks.