Issue With custom Fonts on iBooks

I am using ibooks Author 2.0 and trying to embed the custom font lacartoonerie which is a True Type Font with extension .ttf. However when I preview the book in iPad the font comes for a brief second and gets replaced with some default font. While selecting the font in iBooks Author 2.0 it does not give me a warning message as well.

I read the support article about using custom font, which says that any true type font with the extension .ttf can be embedded.

Am I missing any step?

Regards

Dhaval