I enabled multi-site, then installed this plugin. Eveything looked fine until I checked http://mysite.com/sitemap.xml. It didn't load up in chrome and gave some weird stylesheet error on Firefox.
I have uninstalled the plugin, but intend to use it if there's a solution to the above issue. I came across a site which is using the plugin and getting the same error. Check this - http://journalxtra.com/sitemap.xml
Error loading stylesheet: A network error occured loading an XSLT stylesheet:http://journalxtra.com/wp-content/plugins/xml-sitemap-feed/sitemap.xsl.php?v=3.7.4&url=http://journalxtra.com/wp-content/plugins/xml-sitemap-feed
I was getting something similar.