Paula Abdul's colossal screwup on "American Idol" this week has gotten fans hollering that the judging isn't fair - and has some questioning her role on the show.

Since Abdul commented on a performance by Jason Castro that hadn't been seen by viewers of Tuesday's show, fans and conspiracy theorists alike have been attacking the show's credibility with blistering online messages.

The disgust only grew a day later after Abdul and host Ryan Seacrest blamed the mixup on last-second switches in the production and the fact that Abdul had seen some of Castro's dress rehearsal performance.

"The 'hit' on credibility is much bigger than Paula," wrote a poster named Chickensoup. "Sure, Paula's ridiculous ramblings; critiquing a song Jason had not sung yet, is the big cat out of the bag. It's that her ineptness finally exposed the manipulations of all the executives, producers, Ryan and judges; to the undeniable clarity of how badly this show is fixed.

"If 'A.I.' still had an ounce of credibility, well, it's all gone now."

Neither Fox officials nor "Idol" producers were available for comment yesterday.

Based on the message boards, what pulled at the nails of viewers was the notion that what Abdul or the judges might have been told what to say, or that any of their reactions were scripted.

A poster going by the name PookiAdams wrote on Fox's "Idol" page that the producers want viewers to think everything "is on the up-and-up, when it's clearly not. Of course, they want you to think you're contributing to the show, but you're not in reality - or at least not as much as you're led to believe.... I have watched since season one and this is my last. There is nothing they can do to win me back."

Former "Idol" contestant Jon Peter Lewis isn't buying into the notion the show is fixed.

"I think the idea of the judges being scripted is totally false," Lewis wrote at EW.com. "I've spoken with way too many of Idol's influential people who have expressed genuine surprise at the outcome of a judge's remark or a result ... to think otherwise."

Abdul's giant flub was followed by the least-watched regular Wednesday night telecast this cycle, and the third least-watched "Idol" telecast this season, with 22.8 million people tuning in, according to Nielsen Media Research.

While any network head would kill for 22.8 million viewers, Wednesday's audience is the latest indication that the mighty "Idol" franchise has some issues.

"This show would not be losing viewers if it was a real talent competition," wrote a viewer with the online name Hazardgrl. "It's the blatant manipulations that turn so many people off...I'm out. You just lost a loyal viewer Idol. If you had just let things play out as they would, this season wouldn't have been so awful."