If you name your type as 'service' it wont work. We're working with postgres and the type field is only 6 chars long, 'service' is 7 chars. It will give an error while inserting into the database and the method will never get registered. Were still having problems calling the methods using the procedure specified in the documentation.
I think as of 1.9.x that some of the detail has changed. For example, the 'permission_to_call' method does not exist. --Howard Miller 14:19, 22 June 2009 (UTC)