Can you check in the library location you have on-disk?
If should look something like:
@font-face {
font-family: 'GentiumPlus-R.ttf';
src: url('27.ttf');
}
@font-face {
font-family: 'GentiumPlus-I.ttf';
src: url('28.ttf');
}
We have to create a different fonts.css file for the CMS to use and for the Players to use as the files are stored in different places between the two.
I suspect (and it is only a suspicion) that the fonts.css file in your library location isn’t being updated properly for some reason, but the one the CMS uses is.