When you ask Craig Nicholls how he is, you're not just making pleasant chit-chat. The Vines frontman gained notoriety in May 2004 when a couple of years of antisocial behaviour and car-crash-like gigs, apparently fuelled by lots of drugs and his band's meteoric, hype-tastic rise to fame, reached its nadir at the Annandale Hotel.

That night, Nicholls's behaviour was so appalling - reportedly singing and playing terribly, abusing the audience - that, mid-set, bass player Patrick Matthews walked offstage and out of the Vines forever (he has since become a full-time member of Youth Group) and Nicholls ended up kicking a photographer. The singer was subsequently diagnosed with Asperger syndrome, a condition related to autism that explained his erratic actions.

Sounding like a polite prepubescent, poor verbal grammar and all, Nicholls, 29, now says he's feeling positive and, more pertinently, "feeling good about playing live again". It's a point emphatically made during recent tight, thrilling Vines sets at Homebake and the Big Day Out that showed the Sydney rockers may have finally started to fulfil the promise of their early recordings.

"It was just kind of weird, like a dream," Nicholls says of the band's atrocious gigs before his condition was diagnosed. "The focus, I think, in the early days was much more on the albums than the live show. The live show was just like, 'Right, that's what you do after you've done your album.' Now it's different ... we have just as much focus on the live shows.

"We know what we're trying to achieve now. I'm trying to get my voice to be as clear as possible and not to be so punk and chaotic. There still is that element of it but ... it doesn't dominate the show."

In 2004, Nicholls's annus horribilis, the singer turned 27, at which age some of history's most infamous rock stars, including Jimi Hendrix, Jim Morrison and Kurt Cobain, headed for that great gig in the sky. Was he aware of this?

"Yeah. Someone gave me a newspaper and there was an article, I think it was about us, and there was something about 27. It was like, 'Yeah, what's gonna happen?'

"Maybe there was times in my life when I - without getting all dramatic, ha! - that I sometimes wished that I wasn't around, but that was way before the band. 'Cause when the band came that was great ... I found my reason for existence. I didn't know what I was gonna do and then, all of a sudden, I found, 'Oh, I can do this playing-in-a-band thing all right.'"

Nicholls doesn't take prescribed or illegal medication any more and the benefits have been terrific for the group as well as himself.

The spiky garage rock and melodic, sometimes psychedelic guitar pop of the latest, third Vines album Vision Valley make it a far more worthy successor to their astonishing debut Highly Evolved than their largely forgettable, self-indulgent second album, Winning Days. Both recording and playing live now present a key, welcome difference for the band.

"Yeah, there's no pressure," Nicholls says. "We get to just go and do these festivals" - next stop, the Great Escape at Newington Armory - "and we think the people enjoy it, so we feel good. They're coming 'cause they actually wanna see us. They're aware of the albums or, if not, they know at least a bunch of our songs."

And they still get to see the occasional rock'n'roll-style trashing of instruments, only now Nicholls is in control when he does so.

"It's weird. Sometimes it can be more violent ... but then sometimes it's just for fun.

"We went to England last year and we played and I don't think we really broke a guitar or, y'know, smashed a drum kit. And then it's kinda, it has been happening again ..." Nicholls laughs sheepishly.

"Like, it's that punk thing. I don't wanna say that we're this or that 'cause I don't know what that word [punk] means but I know what it means to me. I wouldn't mind stopping the destruction but sometimes it's the music. Some of our songs can be very aggressive and so [I] get taken over."