Thanks for the tip; I simply installed the font files in LyX.app/Contents/Resources/Fonts, and now it works!
(I installed by double-clicking on each font file, and then choosing "install font" - of some strange reason the font file has been removed from the original location, but it works, so I'm happy)
Peter,
Which font files are you double clicking on? I am guessing you went into LyX.app/Contents/Resources/Fonts using Go To Folder from the Finder.
When I double click on one of these fonts it opens the FontBook application and there is no obvious "install font" option
Are you using OS X 10.2, which does not have FontBook? I am using OS X 10.3.5?
Stephen