First off thanks a ton for nginx, it kicks ass!
/etc/nginx/mime.types line 5 needs to be "text/xml xml xsl rss;" to fix "Error loading stylesheet: An XSLT stylesheet does not have an XML" for firefox users.
See: http://wordpress.org/support/topic/plugin-google-xml-sitemaps-error-loading- stylesheet-an-xslt-stylesheet-does-not-have-an-xml-mimetype-3?replies=9#post -1665218
"xsl" needs to be included out of box so firefox users do not run into this issue. I'm sure a large base of your users are also firefox users.
That is to say if the mime.types does not include xsl and the user is using firefox and tries to view a .xml file the user gets a "Error loading stylesheet: An XSLT stylesheet does not have an XML" error.
The easiest way to see this in action is with the popular wordpress plug-in Google XML Sitemaps http://wordpress.org/extend/plugins/google-sitemap-generator/ and simply generate the sitemap.xml file.
Such a small little change to save so many newbies a major headace of trying to figure this out.
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