InspirioN on "[Plugin: W3 Total Cache] Found 2 bugs in Minify"

I have also discovered a small bug,which for me, who is a rookie, is a bigger bug than it probably is.

I have 4 small social media icons in my header. When I activate the W3TC the icons are there but appear as 4 empty boxes. I mean they are in color but no font inside. Like facebook icon blue but no F inside.When I deactivate the plugin everything goes back to normal.

Any ideas?

Cheers