Seeing Double? This article describes how to correct duplicate featured images.
Many themes display featured images by default, whether you insert it in the post or not. We prefer to insert images exactly where we want and in what format we want. We built Acabado to allow for either preference. If featured images are duplicating at the top of each post you have BOTH preferences enabled.
The easiest way to solve this scenario is to de-activate the automatic featured image generated. See this tutorial for instructions: Using Featured Images