I'm baffled by this. I just tried to use some Zapf Dingbats characters in Numbers (iWork 09 running in OS X 10.8.2) and the letters just come out as a standard looking Sans Serif font. So I opened font Book expecting Zapf to be absent. But no, it's in there and it verifies fine. So I opened Pages and get the same result - font appears in the font menu, but produces standard letter instead of Zapf symbols.