font awsome seems broken?

hello there,
I have installed a theme (ultra) which uses font awesome for its icons all over the site. however, in places where these icons should appear it shows a hieroglyphic thingy, which makes me think the link to the font is somehow broken.
My site is fedplast.com, and you can see where the missing icons should appear in a few places, for example: at the very top, on the right of the menu there should be a magnifying glass to reveal the search box, instead there is a little box. also in the orange “contact us” button there should be an arrow… and so on.
One thing I should point out is the site’s structure: actually I have 2 separate, independent WP site in 2 separate sub-folders of a main directory. and when I moved this fedplast.com site into it’s sub-folder that’s where the awesome font broke…
I hope you generous guys can help, thank you very much in advance!