The Break-Up presents a challenge for the critic. Watching and assessing what's on-screen is hard to do without taking into consideration tabloid musings about the off-screen relationship of leads Jennifer Aniston and Vince Vaughn, and without factoring in the moviemaking process that led to such an atypical romantic comedy.

On the first score, speculation as to whether Aniston and Vaughn are truly a couple, and what their relationship might be like if they are, is unavoidable -- much to the delight of the studio's marketing department. The idea that their relationship could be a publicity-seeking sham raises further questions about them and the industry. Are we back in 1946 when Hollywood bosses and handlers controlled stars' lives? 

Second, the movie's delayed release has allowed rumors of poor test screenings and alternate endings to muddy the waters. Again from a publicity perspective, bad buzz is better than no buzz provided it's sufficiently controversial and tantalizing. Aniston's divorce from Brad Pitt and his natal African sojourn with Angelina Jolie have ensured that’s the case, though Aniston's stand-alone celebrity quotient can't be discounted. 

Leaving aside to what extent it mirrors reality or whether it came to pass by accident, necessity or design, The Break-Up has integrity. It sticks to its guns -- interpret the title literally -- and is refreshingly better for it. That doesn't make for an altogether pleasant viewing experience, however, since the harshly funny relationship realism creates uncomfortable moments that aren't anybody's idea of a fun night out -- and mostly because you're petrified the moviemakers won't have the courage to follow the film's internal logic.   

Mismatched from the word go, two Chi-town singles split and neither is willing to vacate their condo. Aniston's delicate, privileged art gallery worker and Vaughn's Polish-American tour operator don't belong together. (Adding to the "art"/life parallels, Chicago is Vaughn's hometown.) During one of their shouting matches, she says "I don't know how we got here!" Neither does the audience in a crucial sense.  After an opening scene in which he cadges a date at a Cubs-White Sox game (by buying her and her date hot dogs), a montage of still photos is used to show they are a very serious couple. Next stop: Splittsville. Sometimes the relationship math is simple, but all the interesting variables have been skipped over, so while it's no surprise they can't last, it's shocking that they got together in the first place.

Both parties are irresistible in different ways -- he has his patter and she's scrumptiously vulnerable -- yet the union is clearly beyond repair and, correctly, the filmmakers choose not to try and fix it. The problem is there's too much dead air while they decide. Trimming the last third of the movie would have helped. Director Peyton Reed can't inject any of the style that made his previous effort Down with Love, also about incompatible lovers (Renee Zellweger and Ewan McGregor), bearable.

This pair bickers like a married couple approaching their seven-year anniversary, unleashing salvos that would undermine the sturdiest foundation. Their big blow-up happens following an extremely awkward dinner party with their families. Ostensibly, she wants him to show he cares and not take her for granted. Like any normal Neanderthal, he wants to play video games and not be told what to do. She naively believes a game of chicken about splitting will cause him to change his ways. He comes up with too little too late.

Supporting players John Favreau, Judy Davis, John Michael Higgins, and Jason Bateman add funny counterpoint. Yet despite their characters' lack of compatibility and their lack of chemistry as performers (compare to Pitt and Jolie in Mr. & Mrs. Smith), the two lead actors carry the film. Aniston's rear nudity and general sensuousness certainly buoy the proceedings. More importantly, no one wants to see Aniston unhappy and Vaughn is able to convey his regular-Joe hipster charm with a final wink.

There's no avoiding the conclusion that The Break-Up doesn't bode well for their relationship, assuming it's real. Yet a sign of hope and indicator of the movie's partial success is that you exit wanting to believe couples therapy is still worth a shot.

(Released by Universal Pictures and rated "PG-13" for sexual content, some nudity and language.)