Hello wroot.
I didn't test the plugin in development version. I'm using Openfire 3.9.3 and tomorrow I'll release 0.2 that supports tcp connections (port 4455). This is a screenshot of my MRTG that use this feature.
During this week I'll release version 0.3 with debug options. It'll help to identify this kind of problems.
Thank you for testing my plugin and give me your feedback.
Regards,
Marcelo Terres