No stars in snippet; source has everything it needs.

Hi,
I am using Author Product Review plugin for injecting Schema microdata for Product. I have modified that plugin to inject Product ratings and review microdata. Coding is all set, even source of my web page shows everything it needs. But no stars on google snippet( i tested on rich snippet testing tool).
here is a screenshot of my this webpage results.
It shows everything it needs in the details section but no stars and that related structured data just below results snippet heading.
Can somebody help me what is that i have done wrong ?