L-R: Simon Cowell, Dannii Minogue. Sharon Osbourne and Louis Walsh

By Mark Savage Entertainment reporter, BBC News

TV talent show / ritual humiliation vehicle The X-Factor returned for its fourth series this weekend, with a few new twists on the old formula.

The age limit has been lowered to allow 14-year-olds into the competition for the first time, and Australian pop star Dannii Minogue joins Simon Cowell, Sharon Osbourne and Louis Walsh on the judging panel.

You are possibly two of the most annoying people I have met Simon Cowell on brother sister act Same Difference

It is one of ITV1's biggest hitters - the live final has ranked among the channel's top 10 programmes for the past three years - so it is hardly surprising that producers wanted to keep things fresh.

But the basic premise remains the same: a seemingly unending parade of the UK's most deluded, talentless and tone-deaf performers try to drive the four judges slowly mad with their rendition of I Will Always Love You, as performed by a cat, trapped in a bucket. With scorpions.

Auditions

Cowell is not always impressed by the talent on display

Among the hopefuls in the first episode were the irritatingly upbeat brother and sister duo, Same Difference.

"You are possibly two of the most annoying people I have met," noted Cowell after they hammed their way through I'll Be There For You, the theme tune from Friends.

Also lining up to be judged were 79-year-old Joy, who impersonated a Hawaiian guitar through her nose, and Londoner Emily - who turned out to be the most level-headed teenager in the country.

Providing a backdrop to the opening show was the drama over Irish music mogul Louis Walsh - fired from the programme earlier this year.

He was replaced by choreographer Brian Friedman, but Cowell and Osbourne soon realised that something was missing.

"I don't feel any chemistry," complained Osbourne.

Around 150,000 applicants strutted their stuff for the judges

"There's a very, very weird atmosphere," added Cowell before a montage of awkward moments which felt like out-takes from The Office, but with worse dancing.

Eventually, Cowell bit the bullet and called Walsh back to the show.

The Westlife and Boyzone manager hopped on a jet and resumed his position on the judging panel, sporting his trademark facial expression of a confused, but well-meaning potato.

Producers have admitted that some of these scenes may have been reconstructed to "to get the story right".

Cowell said much of the "interesting stuff" was "off-camera" and "happened in my dressing room or on the telephone".

It's still kind of weird to be to be sitting with them Dannii Minogue on joining the judging panel

"It's much more honest to show that stuff than say 'there's lots of interesting stuff but we're not going to show that,"' he reasoned.

At the press screening, Walsh and Cowell seemed to have put their differences aside - sitting beside each other and laughing at their barbed on-screen comments.

'Little Rottweiler'

A record 150,000 people applied for the X Factor's fourth series and, for the first time, they had to face a real-life pop star in the pint-sized shape of Dannii Minogue.

The singer, who Cowell calls a "little rottweiler", says the most daunting aspect of her debut was not the gallery of freakish contestants - but having to find a role in the judging panel.

"I was used to seeing these judges and loving the show," she says. "It's still kind of weird to be to be sitting with them."

Dermot O'Leary replaces Kate Thornton as the show's host

Despite a 16-year run of chart hits, Minogue admits that none of the contestants chose one of her songs as their audition piece.

"They're not melodic enough," she confesses. "They're all dance beats."

"One person did a Kylie song - I think it was Spinning Around - but I don't know if he'll make it into the programme."

The audition process ended earlier in the summer, and successful candidates are already filming the "boot camp" segment of the show.

Eventually, 12 acts will make it through to the studio stage of the competition - competing for public votes and a �1m recording contract.

Cowell is quick to defend the programme's past record, despite a slow release schedule for previous winners Steve Brookstein, Shayne Ward and Leona Lewis.

"We get a lot of stick that we never produce stars," he says, "but we've spent 10 or 11 months in LA and England with Leona, and her record is as good as early Whitney or early Mariah."

Leona Lewis went straight to number one after winning last year

"I said to Leona when she won: 'I'll make a commitment to you, Leona. If it takes two years or three years I'll wait that long. I'm not going to put rubbish out,' and I think we have made a great record."

He is less kind about Steve Brookstein, who was dropped by his record label months after winning the contest.

"To be honest, it was a little bit shallow in the talent department that year," he says.

As an X Factor viewer until very recently, Minogue feels that Leona Lewis has raised the bar for this year's competition.

"People believe in it again," she says. "It could launch an international career."