Problem with the graphs of the Monitoring Service

Hello, I have a problem with the graphs of the Monitoring Service.

  In a server windows 2003 I have installed the Openfire 3.6.0 with the plugging Monitoring Service 1.1.0, the this database in MySql, the case is that all the graphs work correctly except that of the conversations, which alone me presents the information of last 60 minutes, it is necessary to form something in order that they work correctly.

A greeting.