[Zope] LocalFS problems with @import-ing stylesheets

I can confirm the problem, the stylesheet is not rendered from localfs with firefox the problem is caused by an incorect http header "text/plain" instead of "text/css" I've tried to add a type_map to the LocalFS but the content-type does not change so, for me, it is clearly a LocalFS issue anyone knows how to hardcode this content-type in LocalFS.py ?