Export OTF, but glyphs are missing

I am currently trying to customize an icon font from fontawesome.io using the glyphs app. When I open the .otf font supplied by font awesome, and then try to export it (without making any edits) some of the glyphs are missing. Any idea what might cause this?

This has probably to do with the encoding of the glyphs. Can you check “Keep glyphs names form imported files” in Preferences > User Settings and reopen the .otf? This should fix the problem. If not, could you send me the .otf file?

The OTF file is here: (click “view raw” and it should download).

https://github.com/FortAwesome/Font-Awesome/blob/master/fonts/FontAwesome.otf

This is the setting i have:

https://www.dropbox.com/s/6bkphglceu6ewtv/Screen%20Shot%202013-11-15%20at%202.35.00%2 0PM.png

I tried it and it seem to work. What glyphs do you miss in the final font?
And what version of Glyphs do you have?

I’m using Version 1.4.2 (554).

I can see all the glyphs when I open the .otf in Glyphs app, but if I install the exported .otf to my system (OSX Mavericks) and try to use the the font in Photoshop (or any program), some of the icon glyph is undefined.

This is a cache problem. Please read these two articles:
http://www.glyphsapp.com/tutorials/tag/testing