As Craig Nicholls played the introduction to one of his quieter songs at the Annandale Hotel in Sydney last week, he heard someone laugh. The Vines frontman glared at the audience. "Why the f--- are you laughing?" he said. "You're all a bunch of sheep. Can you go baa?"

The audience was stunned. They had already watched the band's bass player walk off the stage after Nicholls kicked out at a photographer during the first song. The crowd knew the 26-year-old singer had a reputation as one of rock's wild men, but face to face in the intimate surroundings of the Annandale, they sensed this wasn't an act.

"People were scared shitless," says Viv Fernandes, a 19-year-old from Maroubra who was among the 450 people who won tickets to the Garage Session concert organised by Sydney radio station Triple M. "But it was fascinating, too. It was a bit like a movie."

The story of the Vines, the Sydney quartet once dubbed the future of rock'n'roll by the British music press, does resemble a movie script. At first it was a rock'n'roll fantasy: two teenage friends (Nicholls and bassist Patrick Matthews) who met flipping burgers at McDonald's and wound up with their faces on the cover of Rolling Stone. A band that played just three songs at their first gig, at Hurstville RSL in 1994, and went on to shift 1.5 million copies of their debut album, Highly Evolved, eight years later.

But in recent weeks, the script has been rewritten. They now seem to be starring in their very own disaster movie.

Nicholls's behaviour at the Annandale prompted an angry Triple M to drop the band's music from their national playlist. "Those 450 people were fans of the music and should have been treated to a show by a band they loved," the station's program director, Mike Fitzpatrick, said. "I was embarrassed for him (Nicholls); he was acting like a child."

It is believed that Winterman and Goldstein, the band's managers, have paid $11,300 to the Sun-Herald to replace the camera Nicholls destroyed when he swung his foot at photographer Janie Barrett. Police are still investigating the complaint Barrett filed against Nicholls after the concert.

The longer term repercussions may be more serious. The Vines were due to play a high-profile gig at the Metro the day after the Annandale show but cancelled "due to illness". It's a bad omen for an act that has received lukewarm reviews of its second album, Winning Days, and has been eclipsed - in the eyes of the fickle British music press, at least - by another Australian band, Jet.

Those close to the Vines closed ranks this week. Neither Winterman and Goldstein nor the Vines' record company, EMI, would discuss suggestions Nicholls is suffering from mental exhaustion or rumours that the band's upcoming US tour will be postponed.

Todd Wagstaff, managing director of Engine Room, the company that signed the band and got them deals with overseas labels - ironically, after seeing them play at the Annandale in November 2000 - was also reluctant to comment. "In terms of what's going on now, there's a lot of exaggeration and misunderstanding," he said.

The truth is that Nicholls's performances have always been an important part of the band's appeal. As the world renewed its love affair with rock'n'roll, a wild-eyed frontman willing to discuss his use of drugs, rip off his shirt and destroy guitars on stage suited the mood perfectly.

Nicholls did little to correct the public perception of him as a maverick who flirted with madness. "It doesn't hurt me if anyone says I'm not normal," he told Rolling Stone. "I don't know what normal is."

The madcap image is slightly at odds with the teenage Nicholls, who worked at McDonald's in South Hurstville. The restaurant's owner-occupier, Simon Osborn, recalls the future star as a "very good employee".

"He did walk around looking like a bit of a deadhead, but it never affected his work," Osborn says.

"Craig's brother and elder sister used to work here as well."

Osborn remembers Nicholls as a "very quiet sort of guy". That hasn't changed. Despite his onstage antics, he's a loner who rarely gives interviews and reportedly spends hours on the tour bus recording new songs on a four-track recorder.

Musically, the band's live performances have been patchy, but the sheer unpredictability of their singer was a reliable drawcard. In August 2002, he threw himself into drummer Hamish Rosser's kit during a performance of their hit single, Get Free, on the Late Show with David Letterman. "Is he all right?" asked an incredulous Letterman. A few months later, the band was ejected from the Tonight Show with Jay Leno before it could perform. Nicholls had damaged the set during a boozy soundcheck.

Matt Rule, a part-owner of the Annandale, was at the Triple M gig. He believes Nicholls was upset at having to perform the "corporate-style show", which kicked off at 7.15pm, a distinctly un-rock'n'roll hour. Rule concedes it was a volatile performance, but considers Triple M's reaction "disgraceful".

"It was real," Rule says. "The guy was feeling something and he let out on stage. It reminded me of some old Nirvana gigs where Kurt Cobain would drawl half the words. But it was a classic live show. It was rock'n'roll."

Nicholls, a devout Nirvana fan, would probably appreciate the comparison. And the Vines may well have the last laugh. As fallout over the Annandale gig continued this week, Winning Days, which had slumped to No.85 on the ARIA album chart, jumped 30 places to No.55.