Like the Mona Lisa, Liverpool and Tom Cruise, the Alamo is a lot smaller than you might expect. Situated in the centre of the bland Texan city of San Antonio, the old mission where 180 local heroes died bravely resisting a vast Mexican army is arguably the only modestly sized object in the entire Lone Star State, reports Donald Clarke

Knock a few rough edges off the crumbling masonry and it would fit comfortably into one of the voluminous buckets in which Texan restaurants serve their medium sodas.

Nonetheless, this pockmarked shack has great symbolic resonance for Americans. The Alamo spirit - similar, I suppose, to that of Dunkirk or the GPO - is often alluded to when any noble but doomed enterprise makes it into the headlines. This was unfortunate for the Walt Disney Company's troubled movie division, whose latest attempt to film the story of the Alamo proved to be the archetypal troubled production.

Originally intended as an R-rated - or 15 - film for Christmas release directed by Ron Howard and starring Russell Crowe, the picture eventually limped out in April as a PG-13 movie directed by the barely known John Lee Hancock, starring Dennis Quaid and Billy Bob Thornton.

By this stage it was already apparent that Disney was not having a good year at the movies. Home On The Range, the company's latest (and possibly last) traditionally animated film, bombed badly, despite being rather good fun. Hidalgo, a tiresome Arabian horse-race epic, did only a little bit better. And this was all before the dreary King Arthur fouled up the company's summer. Mix in the possible termination of Disney's relationship with Pixar, the maker of Toy Story and Finding Nemo, and you have a rather delicious story for the trade papers.

In late March this year, as we gather in San Antonio for a grand première, the media are rather hysterically suggesting that the future health of Disney depends on the performance of this one $107 million (€89 million) epic.

"Usually, when you make a movie, you get a certain grace period before there is interest from the press," Hancock, whose previous film was the modest baseball drama The Rookie, says wearily. "Hey, John Hancock is directing a movie. Who cares? This is a different situation, and I always knew this was going to be a different situation because of Ron Howard dropping out."

It has been suggested that it was Disney's insistence that the violence be toned down, to facilitate a less restrictive certificate, that turned Howard - a recent Oscar winner for A Beautiful Mind - off the project. "Well, we were greatly helped greatly by Ron staying on as producer," Hancock says. "I wanted it to be real, and people have said that it couldn't be real with a PG-13 certificate. The truth is the opposite. You can only show all that violence in slow motion, and I didn't want to do that. I wanted it all to be shot at the regular 24 frames a second."

Though San Antonio is, as everybody insists on telling you, the eighth largest city in the US (and, like everywhere apart from booming Las Vegas, the "second-fastest growing"), it still feels like a small town. The local television station, which is on permanent Billy Bob alert, has posted two frenetically excited young women on the yellow - as in rose of Texas - carpet to report on the comings and goings of the blow-dried semi-entities queuing outside the enormoplex. "I think I see . . . is it? That's the top of his hair, I think. It's Billy Bob! It's Billy Bob! Isn't it?" It isn't.

The front page of the local paper features a story about a historian who seems reasonably content with the film's accuracy. Elsewhere in the local media are reports of complaints about the picture's depiction of the Hispanic characters, though Emilio Echevarría, who plays Santa Ana, the leader of the Mexican forces, tells me that the general is still regarded as a traitor in Mexico, for trading Texas for his own life.

With all this chatter and activity - and the fireworks and the mariachi bands and the barbecue - it is easy to overlook the fact that the film isn't really very good. Thornton is amusing as a laconic Davy Crockett, and Hancock makes good use of the Texan landscapes, but anybody who is not already an expert on the 1836 Texan War of Independence is going to find it all a bit of a bore.

Ironically, it might be a little less wearing if it were a little longer. There were, reportedly, three cuts of the film; the one that has been released, though a lengthy enough 137 minutes, abounds in stunted sub-plots and poorly developed secondary characters. Is this version the result of compromise in the editing suite? "If I had had a cut that made me think the movie has big story problems, and if I had to create a new centre for the picture, then that would be what you are talking about," Hancock says, slightly tetchily. "I would then have had to shoot extra footage, but I didn't have to shoot any extra footage here. There is a total misconception here."

I am very impressed by the way the party-hearty cast - co-star Jason Patric would be arrested the following day in Austin for a mild incident of drunken obstreperousness - seems oblivious to the gloomy press coverage. "Well, I think people need to realise every time an event movie comes out people have to stir up controversy about it," Thornton says. "The fact is that it's just a movie. It is no different from going to an art gallery and looking at a painting. I don't know of any movie or painting that has changed the world. There are still people starving in the world."

Hancock is dismissive of the way the viability of Disney's movie division has been connected to this one release. "The corporate climate with Disney is such that they have to add something in there to make it interesting," he says. "Talking about theme parks isn't exciting, so they hang it on a movie. It's just lazy journalism. It's easy. You have two brand names: Disney and the Alamo. Look, Disney had the most successful year in the history of cinema last year. 'That troubled film unit over at Disney'? Hey, any other studio would gladly take those guys."

Much of what Hancock says makes sense. But, sadly for Disney, The Alamo later proved no ordinary flop. When the film took a pathetic $9.2 million (€7.6 million) on its US opening weekend (just behind the bargain-basement low-brow comedy Johnson Family Vacation), antsy share traders knocked $1 billion (€830 million) off the Mouse House's market value. It is almost unheard of for a single film to cause such carnage in the markets. (One can only speculate as to how unwelcome a film in which the Americans eventually triumph over a weaker nation will be in Europe in the current climate. Let us just point out that The Alamo has gone straight to video in France and say no more.)

So is the company in crisis? Disney's relationship with Pixar continues to be a concern for investors and executives. Hancock was right to point out that 2003 was a great year for the empire, but much of that was down to the triumphant performance of Finding Nemo. And, notwithstanding the healthy returns for M. Night Shyamalan's The Village, if the film division is to turn the year around it will do so on the back of the upcoming The Invincibles, another Pixar release.

The situation is changing daily, but so far Michael Eisner, Disney's chief executive, has rejected a proposal from Pixar that would have altered the financial agreements for the final two films covered by the current deal - The Invincibles and next year's Cars - and required Disney to give up rights to the Pixar library. If the two companies do part ways, this will put Eisner in a very peculiar position over The Invincibles: should the film succeed (and it will), then Disney will profit, but it will look rather foolish for letting Pixar get away; if it fails (forget about it), then Eisner can feel smug as he rifles through his changejar.

Disney is also deep in negotiations with a peevish Harvey Weinstein, head of Miramax, another part of the mouse empire. Should Weinstein decide to set up a new independent company he may bring some powerful directors with him.

There is, however, a final irony that rather strengthens the Alamo metaphor. Some months after the defeat at the mission, Sam Houston's troops overpowered the Mexicans at San Jacinto to reclaim Texas. And last month Disney announced that its profits had jumped 21 per cent in the previous quarter. Like the Texans, the corporation has triumphed after all. Even though the film division has been through, as Eisner himself puts it, "a bit of a cold streak", almost everything else - theme parks, consumer products, cable networks - is booming.

Remember The Alamo? Not if they can help it.

The Alamo opens tomorrow