This is a problem that many have been experiencing on Lyx/Mac. In my case it happens in both 1.3.4 and 1.3.5. There are some workarounds that involve copying some font files from Lyx.app bundle to your user/Library/Fonts directory. Search the lyx-users list and also lyx-devel there should be more detailed instructions. Unfortunately they are not foolproof...in my case it did not work. Good luck,
BUT: there's another problem now: Math symbols becomes garbage! I've tried several fonts and sizes, and the result is the same. The old version (1.3.4) still works fine. (Note: it's just the LyX window that looks strange -- the LaTeX code and the dvi files are just fine).
Steve
