After roaring back with imposing ratings for its season debut on Tuesday, American Idol saw its numbers slump on Wednesday. Although Tuesday's ratings beat last year's opener, Wednesday's were down 11.6 percent from a year ago. Ratings for viewers 18-49 dropped 14 percent from a year ago. Nevertheless, the total number of viewers -- 26.4 million -- beat everything else in sight (last year the second show of the season drew 29.85 million). In fact, together ABC, CBS and NBC attracted fewer than 18 million viewers. At 10 00 p.m., CBS took over the lead with 14 million viewers for CSI NY . But two back-to-back episodes of Ugly Betty on ABC drew fewer viewers than The Jay Leno Show on NBC -- 4.5 million viewers vs. Leno's 5.3 million.