service capacity limit not working

Hi, today I update from lite version (1.4.4) to premium (1.5.5.1) and now the service capacity limit doesn´t work.

My settings are
service capacity = 0 and 10 service providers for the service.

Plugin must work for 10 appointments at same time, right?.

I need to fix this.

Thanks.

http://www.elda.es/citaprevia/make-an-appointment-4/