[Plugin: Events Manager] No thumbnails on list events

Hi,
I need to show thumbnails for my events lists and I’ve tried to upload images directly into the post, I’ve tried to use as featured image, but the thumbnails doesn’t show up. What I need is pretty much the same as seen in this page: http://demo.wp-events-plugin.com/events/

Before you ask, I’ve set already the permissions to upload_event_images in my Users Capabilities screen and also, my /wp-content/uploads folder has 775 permission.

Anyone? Thanx

http://wordpress.org/extend/plugins/events-manager/