I like the idea behind “Rumor Has It…” The 1967 Mike Nichols’ classic “The Graduate” is so lived-in, so authentic, it just oozes the feeling that the events unfolding within actually happened to a real Pasadena, CA family. A romantic comedy revolving around the uncovering of that truth, of a daughter coming face-to-face with the man who slept with both her grandmother and her mother, can’t help but peek a person’s interest.

After watching this movie, though, my interest hasn’t so much as waned as it has been bludgeoned into submission. Rob Reiner has constructed nothing more than another one of his thirty-something fairy tales, only this time he’s forgotten the classic banter or the charming class of “When Harry Met Sally…” He’s taken Ted (working here as T.M.) Griffin’s script and turned it into a Lifetime movie-of-the-week, leaving a fluffy down pillow right in the spot where the picture’s spine ought to be. It is an unfortunate waste of both time and talent, and while not without its charms “Rumor Has It…” still doesn’t add up to anything even close to special.

Pity, because the film does contain two sexy, stirring and bouncily funny performances from both Kevin Costner and Shirley MacLaine. This is the second strong outing for both in as many films this year, he for “The Upside of Anger” and she for the criminally little-seen “In Her Shoes.” Both are just as good this time, turning their potentially one-dimensional characters into flesh and blood human beings with a past I wanted to know more about.

Costner is famous internet billionaire Beau Burroughs, an adventurous and exciting man who may have slept with MacLaine’s two-decades-older Katherine Richelieu while he was still in college. He might have also slept with Sarah Huttinger’s (Jennifer Aniston) deceased mother just one week before her marriage to the woman’s dad Earl (Richard Jenkins, nearly as good here as he was in “North Country”). Why does this matter? Sarah’s mom is Katherine’s daughter, meaning Beau’s already bagged two of the women in her family, and if she’s done the math right he might also be her biological father, a question that can’t help but drive the busy career woman mad.

I’m not going to waste my time or yours digging much deeper into this. Needless to say, complications ensue, many of them leading to the potential loss of Sarah’s fiancé Jeff (Mark Ruffalo) forever. Inspired idea or no, “Rumor Has It…” has absolutely nothing interesting to say. It drifts aimlessly to a preordained conclusion so routine it was probably thought up in committee. Just the thought that the talented Griffin (I still get chills thinking of his and his brother’s script for “Matchstick Men”) had anything to do with this makes me cringe, any wit his writing might have had lost amidst the pummeling banality.

But I can’t blame him for this mess, no matter how hard I might want to try. He was the original director, supposed to making his debut, trying to craft a movie in the same style and tone as Nichols’ lauded comedy-drama. Depending upon whom you want to believe, somewhere early in the production Aniston, Costner, MacLaine or the executives at Warner Bros. had the filmmaker removed from the project planting the far more commercial – i.e. bland – Reiner in his place. Scenes were re-shot, the tone was changed and, by all accounts, the movie took a 180-degree turn from the writer’s original vision.

What really happened I can only guess, and with Griffin’s name still on the piece the split between the studio and him must have been financially amicable. Be that as it may, “Rumor Has Is…” just doesn’t work. It’s slow and forgettable, taking too long to reach a finish that unfortunately for the audience just can’t come fast enough. Reiner hasn’t mad a decent picture since 1995’s “The American President,” and while this one isn’t nearly as pathetic as “The Story of Us” or “Alex and Emma” it’s not exactly one for the resume, either.

It doesn’t help matters that Aniston adds absolutely nothing. After “Friends,” you’d think this role would be right up the actress’ somewhat limited alley. Instead, she walks through the whole thing with a weepy hangdog look of morose longing that’s enough to gag a Mountain Lion with its schmaltzy ferocity. All her emotions, even her climactic ones with Ruffalo, feel false, cloying and syrupy, so much so I couldn’t wait to be free of her.

Luckily, Reiner has Costner and MacLaine. Sure both Jenkins and Ruffalo (who, after this and “Just Like Heaven,” needs to have a long talk with his agent) have a few nice moments, but it is the two aging superstars who provide the spark here. I loved them in this, wanted to see them do more, and even when they had to do the unthinkably stupid the duo still managed to make me both laugh and care, something that does not happen when they’re absent. These are the kinds of performances only true movie stars give, each elevating the film to a place so much higher than it ever could have gone to without them.

If the rumors circulating around the making of “Rumor Has It…” are ultimately more interesting (and probably a whole lot more entertaining) than the movie itself, than so be it, these things happen in Hollywood after all and it's not like they're going to change anytime soon. And, as bad as it all is Costner and MacLaine are such lively, self-effacing performers I at least smiled whenever they were up on the screen. As for the rest, trying to color Reiner’s film as anything other than a disappointment would be idle gossip, and all rumors to the contrary gossiping is one of the few things I just don’t do.