My CSS fonts not previewing in Safari or Firefox?

I am using a special font (Slate Pro Medium and yes I put the code in the HTML head) and, when I export the HTML and clean up the code a bit, it works fine in the Google HTML5 Ad Validator (it's a banner ad) but in Preview for Firefox and Safari, the font gets messed up. It works in Chrome though.

Why is the Preview off?

Hard to tell -- Can you share your Hype document? (Or a simple example of the font)

You've probably seen this, but documentation for adding custom fonts is here:

Had to delete. It's client work.

You can click 'Message' on my profile page here: Profile - Daniel - Tumult Forums to send me a private message, or email