All my infographics (twitter, tumbler, facebook, etc.) are showing up as question marks instead of icons

I've updated everything - Firefox and OS. Text shows up, but some headings and infographics are all showing up as question marks. I've checked all settings - Text encoding is Unicode I've tried checking and unchecking "Allow sites to choose their own fonts". This affects body copy, but not the info graphics and some headings. I think it's a font issue - I'm running the newest FontAgentPro - but I can't seem to fix it.