I'm not sure how YooTheme's HTML elements work, so I really don't have a specific answer there. When you enter the EasyTag, it can't be altered by the editor. Some HTML editors will change characters or do other things to the tags before it actually save the tag. Then, when displayed on the page, JFBConnect can't detect the tag, so it looks like it's not working.
I hope that helps explain and glad you can see that it does work. Of course, if you continue to have issues or need anything else, please don't hesitate to get in touch.
Thanks,
Alex