Just spent an hour trying get my damned Mac to install a font. The system is smart enough to identify both the PostScript and TrueType files as fonts in the Finder -- and it even loads a preview! But try to "Add Font" in the system's Font Book application and you get a SILENT failure.
No dialog. No diagnostic message. And no font added.
UPDATE: I'm not the only one with this problem. A known bug. No response from Apple.
UPDATE2: Just add the files to ~/Library/Fonts. Works fine that way.