Portlets displaying correctly only when vaadin admin portlet is on the page


I downloaded the last version of liferay 6.0.6 and the vaadin admin portlet to update vaadin distribution within liferay.

The admin portlet upgraded the distribution to version 6.7.1. However when I put a portlet using vaadin it is not displaying correctly(tabs and buttons are not showed). But if the admin portlet is added to the same page the portlets behave as expected see second image.

Any help would be really appreciated…