Ang Lee sat in Universal Studios before the release of his $150m comic book opus The Hulk and declared that it wasn't the first weekend of the film's release which really mattered. "I hope it hits every mark of a summer blockbuster," he said. "I hope as much as the studio does that it has playability. They will sell the hell out of it in its first weekend but after that it remains to be tested."

Sure enough, Lee's worst fears were fulfilled. His challenging take on a traditional summer formula broke the record for a June opening with its three-day $62.1m take, but the following weekend fell an almighty 70%. Its three-weekend total of $117m may have been impressive five years ago, but today, with event movies regularly costing $100m-$200m to produce and at least $50m to release in the domestic market, a 17-day gross of $117m is considered disappointing.

Therein lies the rub of the summer box office in North America this year. Opening weekend records tumble week after week, but it's the second weekend that counts.

Only one film - Disney/Pixar's Finding Nemo - has shown legs (or is that gills') with its $274.9m take after six weekends the highest of the year so far. Even Warner Bros' The Matrix Reloaded, with its gross of $271.9m, is considered an underperformer since its production costs were so huge, although its international take of over $410m pushes it way into the black.

Media commentators are coming up with their own theories about what has gone wrong this summer. "It's clear the public is wearying of the incessant string of blockbusters rolling off the assembly line," said Lou Lumenick of The New York Post this week. "It's a pretty scary proposition," added Patrick Goldstein of The Los Angeles Times on Tuesday, "but is it possible that the average 16 year-old has better taste in movies than most of the rich, Ivy League-educated studio executives who've flooded us with a deluge of movie sequels this summer'"

The accompanying chart shows the tumbles most of the summer hopefuls have been taking in their second and third weekends. That short attention span on the part of audiences is one of the reasons why the first six months of 2003 are down 7% on the same months of 2002. Even July 4 weekend, with a $72.5m opening for Terminator 3: Rise Of The Machines, was down 11% on the same weekend last year.

That pattern is one which is starting to replicate in the international markets. The need to capitalise on US-generated buzz, star publicity availability and the threat of piracy have all compelled studios to release movies if not day-and-date, then at least within a few weeks of the US. That, says Fox international theatrical president Scott Neeson, is compressing the international play period into the same May to August crunch as domestic.

"We used to have a much more extended play period going into October but now the blockbusters are opening week after week in foreign territories and falling off much quicker than they used to," says Neeson, who adds that the cost of striking all-new prints for day-and-date releases is running into the "many millions of dollars." "We want to go as wide as we can, but that involves a huge increase in print costs and presents enormous logistical challenges."

So can summer 2003 redeem itself' Disney's movie-of-a-theme-park-ride Pirates Of The Caribbean and Fox's The League Of Extraordinary Gentlemen vie for supremacy this weekend, and all eyes will be on the $175m T3 to see if it can hold up in its second weekend. Other megapictures to come include Bad Boys 2 and SWAT from Sony, Tomb Raider 2 from Paramount, Seabiscuit and American Wedding from Universal and the eagerly awaited Lopez/Affleck romantic comedy Gigli. Ironically the picture with the biggest excitement surrounding it is Seabiscuit, a serious depression-set drama about US horse-racing folklore starring Tobey Maguire. While that picture is getting early Oscar talk, the big sequels and spin-offs are only worrying about how far they can get out of the gate.