Error when I put image at the end of the post

If, for example, I have an image, or multiple images, as last stuff that I put in my post, after all the words I wrote, End of post ads aren’t working properly. It seems that plugin is searching for last words, and tries to place ads after the last word in article, so I get a mess, where ads are showing over social network buttons, tags, and last articles. If I put a single word at the end of the article, after images, everything backs to normal, and ad is shown properly.