StyleManager is free to use, but by default processed styles will have a few comments inserted at their beginning and the first load of your website will fire off a tracking request. These comments and tracking requests can easily be disabled by registering StyleManager. Registering StyleManager effectively removes all references to "StyleManager" for the average user and grants an unbranded solution.
There are two registration licenses. You may register for a domain (e.g. www.grovebranch.net) or purchase an "unlimited" license, which will work for any sites you develop.
If you think everything is correct and it's still not working, then please don't hesitate to write to "firstname.lastname@example.org". Your issue will be addressed absolutely as soon as possible.