Blame it on the weather. Blame it on everybody traveling and Christmas shopping.
Or just blame it on the movies.
With the domestic box-office off about 4 percent from the same weekend last year, Disney's "Tron Legacy 3D" led the market, grossing an estimated $43.6 million over the weekend, according to studio estimates.
The follow-up to 1982 cult non-hit "Tron" matched the low side of its pre-release tracking, but it did not meet the lofty expectations of even 3D skeptics like BTIG Research's Richard Greenfield, who predicted the sequel would be a huge 3D hit coming out of Comic Con last summer.
In second place, Warner Hanna Barbera 3D cartoon adaptation "Yogi Bear" grossed an estimated $16.7 million, missing studio hopes of a $20 million-plus weekend.
But the most conspicuous miss of all happened over at Sony, where James L. Brooks ensemble comedy-drama "How Do You Know" way undershot its dour tracking and appears hard-pressed to earn back what became a $100 million production budget after stars Jack Nicholson, Paul Rudd, Owen Wilson and Reese Witherspoon got paid full rate.
The film grossed just $7.6 million this weekend, earning a stinker "C-minus" grade from movie customer-satisfaction survey firm Cinemascore.
"We're disappointed," conceded Sony worldwide distribution president Rory Bruer. "We've had such a great year."
Here's how the top 10 at the box office shaped up. Full report continues below chart:
From "Karate Kid" to "Grown Ups" to "The Other Guys" to "Salt," Sony cranked out a steady stream of hits throughout 2010 … but then came December.
Last weekend, the studio experienced the soft $16.5 million debut of Angelina Jolie/Johnny Depp caper drama "The Tourist," a performance mitigated by the fact that the $100 million production nut was largely the problem of producer GK Films.
As for "How Do You Know," Sony officials expressed confidence that things might turn around in January, when the film gets released internationally.
But one rival-studio executve noted, "I don't think this movie is going to travel well."
Brooks' last effort, 2004's underperforming Adam Sandler movie "Spanglish," grossed only $12.3 million internationally.
As is often the case for this time of year, some distributors attributed some of the market's softness to bad weather, but the environmental forces were even harsher last year, when inclimate East Coast weather stunted "Avatar's" $77 million start.
Better news came out of the adult-drama world this weekend, where the David O. Russell boxing biopic "The Fighter" grossed $12.2 million while expanding from four to 2,503 theaters.
"Hats off to Relativity for giving us such a great movie," said Don Harris, general manager of distribution for Paramount, which is distributing the film for producer Relativity Media after opting not to back the $25 million Mark Wahlberg/Christian Bale film itself.
Despite "The Fighter's" sports theme, the movie garnered an audience that was 53 percent female this weekend.
"That was a surprise," Harris noted.
Among other adult dramas, Lionsgate debuted Nicole Kidman/Aaron Echhart child-loss drama "Rabbit Hole" in five theaters spread across New York, L.A. and Toronto, recouping just an $11,000-per-screen average.
The studio is hoping the film plays like its 2007 Julie Christie film "Away From Her" (uplifting topic: Alzheimer's!), which started out to only $8,800 per location but ended up with a solid $9.2 million worldwide gross.
Also expanding this weekend, Fox Searchlight's Darren Aronofsky-directed "Black Swan" grossed a solid $8.3 million in 959 theaters, while The Weinstein Company's "The King's Speech" grossed an also-strong $1.1 million playing at 43 locations.
Jumping back to the big tentpoles, "Tron" garnered a decent B-plus from Cinemascore, while commanding an audience that was 66 percent male and 82 percent 3D-ticket-buying.
Budgeted at $170 million, the film opened up internationally to $23 million, covering about half of foreign territories.
It performed best in IMAX theaters, where it grossed $10.3 million this weekend at 234 locations. Overall, IMAX accounted for nearly 24 percent of "Tron Legacy's" opening gross, the chain's biggest proportional contribution yet.
With Fox's "Chronicles of Narnia: Voyage of the Dawn Treader" fading 47 percent in week two to $12.4 million, and Fox's "Gulliver's Travels" not expected to make a huge dent in the family market next weekend, Disney officials are hoping for solid play for "Tron" through Christmas and New Years.
"Starting tomorrow, 65 percent of kids are out of school for the holidays," noted Disney worldwide theaterical distribution president Chuck Viane.