A hangover from the TV writers' strike, viewers' increased reliance on digital video recorders and the onset of warm spring weather in daylight saving time are all possible culprits in television's depressing week.

"American Idol" was seen by 22.8 million people April 30. While still enough to be the second-most-watched show of the week (after the April 29 "American Idol"), that's the smallest audience Fox's superhit has drawn for a regular night in more than two years, according to Nielsen Media Research.

"Idol" traditionally takes a ratings dip before the final shows. This year's competition is down to its final four singers.

CBS' "CSI: Crime Scene Investigation" had its second-smallest audience ever for an original episode aired in its traditional Thursday time slot, Nielsen said.

"CSI: Miami," seen by 13.9 million people, had the smallest audience in the series' history.

ABC's "Grey's Anatomy" struggled, too. While still a top 10 show with 15.3 million viewers, that was its smallest audience since moving into its Thursday time slot in fall 2006.

CBS led the way, averaging 10 million viewers. Fox, with 9.4 million viewers, won among the 18-to-49 demographic for the 17th straight week, the longest streak since NBC in 1996. ABC averaged 9.2 million viewers, NBC had 6.5 million, the CW 2.6 million, My Network TV 1.2 million and ION Television 450,000.