Charis font not being displayed

[Canorka]

I've started having a problem in the past few weeks with my original Kobo, perhaps (but perhaps not - my memory is fuzzy) since the update to 1.8, where many books will not be displayed in the Charis font as seen in ADE/Sony Reader software. Instead, I just get the regular Kobo Times New Roman font. This happening with most but not all of the books that have the Charis font embedded. Has anyone else experienced this, or can anyone venture to guess what is going on? I really like the look of Charis on the Kobo, and it actually makes reading a little easier, so I'd like to "restore" it to the books in question if possible. Thanks in advance!