[Plugin: WordPress Popular Posts] Some posts show "No Thumbnail" image and some posts show

I have made the script/cache files writable with 777. For some reason, it is not reading the first image in some of my posts. These images are in my post using <img> tags, they are not within captions etc.

You can see in my sidebar if you click on “Popular” that some posts show the “No Thumbnail” icon instead of the first image in the post.

http://www.interiordesignpro.org/blog/

You can also check the source code for the posts where the images cannot be read to see if I have in fact done something wrong.

I have read all the related no thumbnail threads and the FAQ. Still, I am unable to resolve the issue that some posts show thumbnails and some do not. Thank you for any help in resolving this issue.