Enabling SVG files under windows IIS

I had a similar issue using IIS and it was caused by a 404 error on the SVG files. IIS won't serve unknown file types and the type for SVG files (image/svg+xml) isn't included by default.

 http://www.iis.net/learn/manage/managing-your-configuration-settings/adding-ie-9-mime-types-to-iis
 http://piwik.org/faq/troubleshooting/faq_17051/
 http://forum.piwik.org/read.php?2,101488