Astute readers of’s American Idol TV Watch pointed out on our message boards that only 11 of the 12 female semifinalists were in the audience during last night’s men’s semifinal performances. Missing from the group: Carly Smithson (pictured), the Irish-born songbird who’s been under intense media scrutiny because of her one-time deal with MCA Records, which resulted in Ultimate High, the 2001 flop (it sold only a few hundred copies) she recorded under the name Carly Hennessy.

But conspiracy theorists wondering if the controversy got Smithson booted from the show should hold their horses. Randy Jackson, who dropped by headquarters to shoot an episode of Idolatry this afternoon, attributes Smithson’s absence to a flu bug that had hit several female contestants this week. “I think they didn’t want them infecting the others,” Jackson said. “They were doing sort of an Idol quarantine.” Asked if viewers were in for a surprise on tonight’s women’s semifinal show, Jackson couldn’t have been more adamant: “No, no, no, definitely not.”

A Fox spokesperson confirmed Jackson’s report, adding that Smithson’s fellow semifinalist Kristy Lee Cook also left the audience midway through the evening because she was feeling ill.