The recent hue and cry over NBC's decision to shake up its late-night lineup next year has left some ad buyers scratching their heads, Advertising Age indicated in its edition out today (Monday). In its headline, the magazine observes: NBC Fixes the Only Part of Its Schedule That's Not Broken: Late Night. Underlining that assessment, RJ Palmer advertising executive Marc Morse told AdAge: NBC is not No. 1 in morning, it's down in daytime and evening news, and struggling in prime time. Late night is its only advantage. ... I don't think they need to pre-sell the change a year-and-a-half in advance. Moreover, ad buyers contacted by the magazine noted, it's by no means certain that Jimmy Fallon will draw substantially more younger viewers than Jay Leno -- and they will certainly wait to see how the transition unfolds.