Komento not working on Virtuemart

I am using Joomla 2.5 and virtuemart 2. But I found that Komento seems not showing on the product pages. I tried to use default template and it works, but the self-review system from Virtuemart still exist.

I dont want to use default template, how can i do so that the Komento can integrate Virtuemart well? I searched the forum and tried to add the code "echo $this->product->event->afterDisplayContent;
?>" within the /templates/yourtempltename/html/com_virtuemart/productdetails/default.php), but nothing happen. Is there something else I missed?

Thank you in advance for your help.