With the cast list seemingly falling apart in public and the studio apparently forcing actors out due to low pay, is Iron Man 2 becoming the movie that'll end Marvel's run of movie successes?

If nothing else, the increasing to-and-fro surrounding the cast of the sequel to last year's best superhero movie (Don't groan, Dark Knight fans, you know it's true in your hearts) is becoming an unexpected black eye on the previously perfect public face of Marvel Studios, which only months ago was looking like one of the most successful independent studios in the business and unable to put a foot wrong. Perhaps we should have seen the warning signs when Terrence Howard was unceremoniously replaced by Don Cheadle, and Howard's public confusion over the move was met by somewhat dirty leaks from studio insiders, but even so; that seemed like a one-time thing at the time, instead of the start of a trend.

Since then, of course, Samuel L. Jackson has hinted that Marvel are not bringing him back to reprise his role as Nick Fury, despite Fury appearing to be central to the planned Avengers movie (especially if it's as close to Mark Millar's Ultimates comic as has been rumored) because of a breakdown in negotiations over money. Just over a week later, Variety announces that the studio has offered Mickey Rourke a stunningly low $250,000 to play one of the two lead villains in Iron Man 2... a move that led, earlier this week, to Rourke saying that he wouldn't be doing the movie after all (The usual anonymous sources are saying that the deal isn't necessarily dead just yet).

Marvel, of course, haven't officially commented on any of these situations - and it's unlikely that they will, particularly as the Rourke and Jackson negotiations are still, officially at least, ongoing - but the fact remains that Iron Man 2 is beginning to look like a movie that's being hamstrung by accountants with their eyes staring a little too intently on the bottom line. This isn't exactly news - director and co-writer Jon Favreau has also complained about being lowballed by the studio in their initial offer to sign him for the sequel - but at this point, it's getting embarrassing for Marvel; the only actor who's not complained about the progress of the movie has been Robert Downey Jr. himself (Gwyneth Paltrow has griped about not having seen a script yet, and the production seems to be having trouble keeping the love interest that they cast... but at least neither of those are money-related).

We're still a year away from the release of the movie - Iron Man 2 is scheduled to open May next year (Although, let's face it, that date may end up being as unrealistic as Favreau publicly declared it when it was first announced) - but that doesn't change the fact that Marvel needs to either start coughing up some more money for this movie - and considering the first made close to $600 million, that shouldn't be too much of a struggle - or else start putting together a more convincing PR push to explain that everything's going to be alright in the end. Because, right now, it's not looking as if Tony Stark's second outing is going to be quite as bulletproof as his first.

Send an email to Graeme McMillan, the author of this post, at graeme@io9.com.