1. Turn on firebug or developer tool in the browser and go to console;
2. Open up sakai integration demo: http://build.fluidproject.org/infusion/integration-demos/sakai/html/pager-site-setting.html
3. This error is reported in the console:
"NetworkError: 404 Not Found - http://build.fluidproject.org/infusion/integration-demos/sakai/css/none"
One reason (but may not be all) is that in the infusion/integration-demos/sakai/css/base.css, this line appears at various locations: