When DreamWorks announced in May that it planned to make a movie about Martin Luther King Jr., it took less than 24 hours for the prestige project to hit a speed bump.

Two of King's children disputed a third's authority to speak for the estate, and soon enough King's own words came to mind: All progress is precarious, and the solution of one problem brings us face to face with another problem.

Granted, putting someone's life story on film hardly compares to the struggle for civil rights. But the biographical movie is a uniquely frustrating beast. Discovering a fascinating life story is the easy part, but acquiring the appropriate life/film/art/music rights, appeasing relatives' and audiences' expectations, persuading financiers to ante up and actually making money on the project can be as arduous a task as universal equality.

This is why, despite their undeniable magnetism at awards time, few true biopics ever make it to the big screen. However, that never has stopped anyone from trying.

In DreamWorks partner Steven Spielberg's case, he acquired King's life rights and access to his intellectual property and speeches, but the threatened legal action and King family infighting could affect the project. For its part, DreamWorks says it is undeterred and confident differences will be worked out. We remain committed to pursuing a film chronicling Martin Luther King's life provided that there is unity in the family so we can make a film about unity in our nation, the company has stated.

There are at least three dozen biopics lining the benches of major studios, though not all are actively being developed. Those swelling ranks might be a function of our 21st century addiction to celebrity, but just as few finished products will make it onto a screen as 30 or 50 years ago. Musicians remain a popular target because of the built-in ancillary boost from their soundtracks.

Currently, producers and studios are pushing personages as diverse as Kurt Cobain, Abraham Lincoln, Nina Simone, Marilyn Monroe, Liberace, Hugh Hefner, James Brown, Theodore Roosevelt, Lance Armstrong, Ian Fleming, Joe Namath and Milli Vanilli toward a green light.

We always have liked stories that are about the triumph of the human spirit, says Howard Baldwin, who produced the 2004 Oscar nominee Ray, about Ray Charles, and is working on projects about hockey icon Gordie Howe and Redwoods-saving activist Julia Butterfly Hill. So, if we do a biopic, it's usually going to be about that. Somebody that's able to overcome obstacles and triumph is a good story.

That could describe anyone who ever has tried to make one. (Yes, the definition of biopic can be stretched in several directions. Does Out of Africa qualify? Erin Brockovich? What about Braveheart, Julie & Julia or Schindler's List? Talk amongst yourselves.)

Obstacles are built into the very concept of the genre: For the most part, one can't simply stick one's version of someone's life onscreen without permission. Navigating various rights issues takes diplomacy.

One Monroe project with star interest hit a snag when writer-director Andrew Dominik adapted Joyce Carol Oates' Monroe-inspired novel Blonde on spec before acquiring film rights. It remains in limbo.

A Simone project at Paramount/MTV Films has a similar high-octane star interested and a writer working on the script. But they've got an eye on a court case being fought by the late singer's ex-husband and lawyer over the rights to her songs.

Producer David Permut's aggressive mid-1970s pursuit of Janis Joplin's music and life rights -- he already had film rights to Joplin's biography, Buried Alive, by Myra Friedman -- was an adventure in itself. The quest led him from sharing a San Francisco sauna with younger Joplin siblings Michael and Laura and their lawyers to playing all-night billiards at a converted whorehouse before he finally got the family's blessing.

It was a long, winding road, Permut says. The upshot? Bette Midler decided to make the thinly veiled version of Joplin's life, The Rose, at Fox instead, and Permut's project suddenly was as dead as his subject.

In May, Martin Scorsese officially came aboard Universal and Mandalay's Frank Sinatra project, which had been bogged down not only in a complicated negotiation over rights to the iconic singer's music, but also rights to apparel sales. Phil Alden Robinson (Field of Dreams) now is crafting the screenplay.

Universal's Cobain biopic required the negotiation of book rights, life rights, music rights and widow Courtney Love's rights to same. David Benioff (Brothers) is working on the script.

Every one is a negotiation and a process, and on a bio you tend to get bogged down on creative only because it's a person's life, Baldwin says. Just sitting with the people whose life you're talking about and getting them comfortable -- trust is really important.

Even if rights are sewn up properly, the material provides its own problems. Often, an intriguing life story looks enticing on paper until a screenwriter tries to bend it into a movie form that remains true to history without whitewashing it or offending fans and families. Rarely do real lives snap into a three-act structure.

The trick to writing or making a biopic is: Don't make a biopic, says screenwriter Christopher Wilkinson, who with partner Stephen Rivele has written Ali and Nixon and is developing biopics about Miles Davis, Hugh Masekela and Jackie Robinson.

Meaning, it has to be something else that's bigger than the life that you're writing about, he says. The details of someone's life are just not that interesting. You really have to cut the line between making a compelling drama and being truthful to what actually happened. Facts are boring; the truth is fascinating.

Adds Permut: If you're dealing with noteworthy people, historical figures, you have to tell a story that hasn't been told. Get under the skin.

All those unknown stories sometimes can lead to multiple teams of filmmakers pursuing the same subject. Lincoln, for one, has four treatments in the works: Spielberg's Doris Kearns Goodwin-derived version; a Christopher McQuarrie-scripted look at John Wilkes Booth, Lincoln's killer; an adaptation of American Gothic, a book about the Booth brothers; and a Robert Redford-directed film, The Conspirator, that recently began casting.

McQuarrie was involved in another bio matchup when his work with Scorsese on an Alexander the Great movie was overtaken by Oliver Stone's 2004 version.

Among the advantages of the genre is that if a compelling story can be shaped from the raw material, it often attracts major talent driven either by passion or ego to take the role of a complicated artist or iconic outsider. It usually is the only way the project will draw financiers and distribution.

It's very tricky, says director Karyn Kusama, who has been trying to put together a project about New York assemblage artist Joseph Cornell. Either the life is so recognizable that it becomes a selling point of the title, or the life is so rich that you can do something with it where the story becomes the star. Kusama hopes to build her project in the latter mold, showcasing the changing city that Cornell scavenged during his long career.

For every Walk the Line or Coal Miner's Daughter that has captured critical and commercial praise, there is a W. or Frida that didn't attract much of either; then there are musical icons, such as Jimi Hendrix or Joplin, that have managed to elude cinematic portraits.

In an era awash in source-material addiction, most bio projects have brand awareness much in the way a best-selling book does because the audience already has knowledge or curiosity about the subject. On the other hand, most such films don't travel well because they're so specific to nationality.

Ray garnered awards attention in the U.S. but grossed only $37 million abroad; the Harvey Milk biopic Milk took in $20 million overseas. Even Scorsese's lavish The Aviator, his take on Howard Hughes that starred Leonardo DiCaprio, grossed just $71 million foreign ($103 million domestic).

That math -- combined with the near extinction of the midbudget drama and disappearance of the TV movie -- is why each studio trots out a biopic only once every few years, passion project be damned. Says one studio exec surveying the field of such projects out there, The biopic is dead.

But then, in Hollywood, dead doesn't really mean dead.