Before/After selectors not showing resources

I’m setting up a site using the Vertikal theme, and I’m having some trouble with the images not showing for the Before and After Selector css tags.

We have two similar urls that the site can be accessed at (but they’re pointing to the same site & wp install). When you navigate to the site using one url, it looks fine. With the other, all the image resources used by the ::before and ::after css selectors fail to load. Looking at the CSS shows that apparently the images are stored in a resource library; the CSS looks like this:

.fa-envelope-o:before {
content: “\f003”;
}

Thanks,
Bob