DEBORAH LIPSTADT, a professor of modern Jewish and Holocaust studies, is one of the most popular faculty members at Emory. But what really sets her apart is a book written a dozen years ago in which she lambastes one of the worlds most infamous Holocaust deniers, David Irving. Irving turned around and sued Lipstadt for libel in British court, but the judge found in favor of Lipstadt, calling Irving a racist and anti-Semite. Sweet. Lipstadt was back in the news last spring when she refused to allow C-Span to tape a lecture she was giving. Why? The network wanted to air it back-to-back with one by Irving. Seems the battle against Holocaust deniers isnt over yet.