A Search Engine Watch Forum member posted a thread named Yahoo.it censored for 'preteen'? Basically, if you do a search on the term "preteen" in Yahoo! Italy (image), nothing comes up, but the same search at Yahoo.com (image) brings up results.
Danny Sullivan ventures a guess that "Yahoo got some complaint, perhaps a legal one, about child porn sites in its results in Italy."
Who knows for sure, could be some whacky glitch or something.
Forum discussion at Search Engine Watch Forums.