Hello, congratulations for the plugin is truly complete
Let me explain my problem, I have done the following:
1) I imported some posts in my blog with the instrument import in xml
2) I copied the images from the old to the new blog, in the folders "\ wp-content \ uploads"
3) I used the tool search and replace to rename the url of the image you just imported
4) the post work properly and the images are visible
5) while the thumbnail of "WordPress Related Posts" only for the imported posts do not go out and uses the default images folder "\ wp-content \ plugins \ wordpress-23-related-posts-plugin \ static \ thumbs"
Can you help?