Ti risulta? se così per me potrebbe andare già bene, mi risolverebbe il problema.

Internet Explorer 7 and below don't support media selectors on @import rules, instead ignoring the entire rule when they are present. Therefore, you can create an entire stylesheet for non-IE browsers and import it into your main stylesheet by adding @import "non-ie.css" all;.
su http://www.webdevout.net/css-hacks#in_css-import_media