Plagued by a drop in viewership and the widespread perception that this year's crop of singers was.

one of the weakest in the show's history, "American Idol" is facing another problem: Sluggish ticket sales for its summer tour.

Although no one has officially disclosed the reason, Live Nation has canceled at least a half-dozen shows on the "American Idols Live Tour."

And it's quite apparent that ticket sales have been slow, based on the availability of good seats at various venues and promotional offers for discounted tickets.

In addition, the tour run has been shortened by two weeks, so some of the dates of the later shows have been moved to earlier dates,The schedule changes do not affect the two New Jersey shows on the tour: Atlantic City's Trump Taj Mahal this Saturday, July 10, and Newark's Prudential Center on Tuesday, July 20. Also, the Philadelphia show is still on for Sunday, July 11, at Wachovia Center. (Earlier tonight, good floor seats were still available for $70.50)

Idol shows have, however, been canceled in Buffalo, Cleveland, Kansas City, Omaha, Neb., Toronto and Winnipeg, and dates have been switched in Chicago, Des Moines, Iowa, Minneapolis and Toledo, the AP reported.

The summer tour, a longtime tradition of the high-rated reality show on FOX, features the top 10 singers of Season 9: Lee DeWyze, Crystal Bowersox, Casey James, Michael "Big Mike" Lynche, Aaron Kelly, Siobhan Magnus, Tim Urban, Katie Stevens, Andrew Garcia and Didi Benami. DeWyze won this year's contest, surging past runner-up Bowersox in popularity polls during the final weeks of the season.