There seems to be a problem with repository manifesting with plugin SEO Friendly Images
WordPress page indicates version 2.6 is latest, which is what the plugin update also indicated, but both automatic update and the download link http://downloads.wordpress.org/plugin/seo-image.zip Download version 2.4.4
Many users have complained they can not upload the plugin through automatic update. Version 2.6 can be downloaded normally through 'Other versions' link http://wordpress.org/extend/plugins/seo-image/download/
Just the main archive file seems to be broken.
I appreciate your response.