Minification in Hummingbird Safari Issues

When we enable minification in hummingbird, the CSS does not fully load in Safari.

This happens on a couple of sites that we have 'minified' the css, etc. on. However, the issue is ONLY in Safari on Mac. It works in every other browser on Mac and no problems on PC. I love the impact this has on speed, but the site can't be broken on Safari. Are there any other steps I could take to help save speed, but load properly on Safari? Thanks...