Who'd ever guess that timeless beauty Michelle Pfeiffer would actually have to consider the age old question.

"Yeah, age," says Pfeiffer, "29 was harder than 30, and maybe 39 was harder than 40.

"That, and the fact that the press already had me turning 40 for the longest time, made it easier. So when I did turn 40 a while ago it didn't really matter."

Time still matters to Pfeiffer, however. And while she might not pay much attention her own clock ticking, she came to the realization that there was a creative limit on how long she'd have to do certain roles in certain movies.

Like the sister role in the film version of the Pulitzer Prize-winning Jane Smiley novel, A Thousand Acres, which opens Friday.

"It was six years in the making," says Pfeiffer, who spearheaded the project with her co-star and buddy Jessica Lange.

"We had been looking for something to do together when this book came up."

Schedules plotted against them. And while Pfeiffer and Lange are considered bankable movie stars, the unrelenting sadness of the story "frightened" most of the major distributors.

"It is not what the studios are clamoring to make," confirms Pfeiffer. "It's not a romantic comedy and it's not action, and they are reluctant to make anything that scares you emotionally."

What A Thousand Acres does, too, is challenge the conventional wisdom of the American midwest dream since the book and the Jocelyn Moorhouse-directed film deal with a proud farmer and his three daughters, and their nightmarishly dysfunctional lives.

Besides Lange and Pfeiffer, Jennifer Jason Leigh plays another sister. Jason Robards is the father. Colin Firth, Keith Carradine and Kevin Anderson are the men in their lives.

"It's a real testament to the material that the movie got made at all," Pfeiffer suggests. "We really got discouraged at some points."

The delays and discouragements became so frequent that Lange and Pfeiffer were about give up the rights. That's when time and place conspired for them, not against them.

That's why she refuses to get angry or frustrated when the male bashing question is brought up. Undeniably, fathers and husbands do not come across well in the book and film.

"But the women aren't exactly perfect either," Pfeiffer points out. "We're not saying that some American families can be pretty perverse, and pretty dark, because a lot of things go on behind closed doors."

Not surprisingly, Pfeiffer was focused and more than a little finicky on the Illinois set, dealing with the tragic melodrama of her character.

Her two kids, Claudia Rose, 4, and John, 2, were with her, but she found the shoot difficult, demanding and a little unsettling at times.

"I wasn't pleasant to be around," she says. "And whatever patience I had I saved for my kids, so you can imagine how I treated everybody else. As it is, a whisper becomes a shout on set anyway."

But the movie got made, and was filmed relatively incident free. Post-production was another matter.

Actors and producers, Pfeiffer and Lange, wanted the film cut back and cut closer to the narrative of their characters. Moorhouse disagreed, but relented under protest, and subsequently did not make herself available for interviews a few weeks before the release.

Pfeiffer and Lange acknowledge the hassle on Moorhouse's behalf. And Pfeiffer agrees that the editing job was difficult. "It was such a delicate balance," she says, stressing the story of the three sisters was important to her, and less so to Moorhouse.

"I'm the eldest of three sisters," says Pfeiffer, who didn't grow up in a screwed up family, but relates to A Thousand Acres.

"I'm like all three of the sisters in the book. I'm a caretaker, but I'm the outspoken one, rebellious. And I'm the one who left home, and fell away and disengaged at a young age." Twenty years later, and Pfeiffer smiles. "I don't think I know any more now then I did then."