Is there trouble already brewing for the newly appointed fourth "American Idol" judge Kara DioGuardi? Idol producers announced Monday that the Grammy-nominated songwriter will join Simon Cowell, Randy Jackson and Paula Abdul at the judges' table when the show premieres its eighth season on the Fox Network in January. | Video

DioGuardi, who has worked with Christina Aguilera, Gwen Stefani and Kelly Clarkson, started as a singer, but eventually carved out a niche in songwriting. In a conference call with reporters, she talked about her judging style, but also had to deal with questions about the Paula factor.

Abdul's sometimes incoherent behavior has raised eyebrows in recent seasons, and interviews she has granted have become increasingly loopy, leading to speculation that she might be replaced. Producers quashed the rumors, saying Abdul wasn't going anywhere.

The choice of DioGuardi is interesting because of her connection to Abdul: Earlier in DioGuardi's career, the two co-wrote "Spinning Around," a No. 1 hit for Kylie Minogue in the United Kingdom. DioGuardi said Monday that she hadn't yet sat down with the three judges for a chemistry test run, and she hadn't yet spoken with Abdul.

"I've always had a great relationship with Paula," DioGuardi said. "I can't imagine her not being happy with it. … We were friends, and she was very instrumental in my career in the beginning."

But Abdul was singing a more cautionary tune on a morning radio show Monday. According to Us magazine, she told listeners on Phoenix radio that she was excited about the new judge, but "I am concerned about the audience and acceptance. Time will tell. We'll see."

After being told of Abdul's remarks, DioGuardi said she wasn't concerned. "She's on a big, big show, and she's just probably pondering what could or could not happen."

So why a fourth judge? Producers "wanted to try a change," Abdul said in her radio interview. "They always tried for a fourth judge because it followed the format of the original show, (Britain's) 'Pop Idol.' We haven't had much luck with that working, but we're going to give it another try."