I am the author of the ravatars plugin which generates random avatars. A few of people who have installed the plugin are reporting that the avatars generated by my plugin are not displaying. Looking into it further we discovered that the avatars are being created and saved properly into the wp-content/plugins/ravatars/cache directory. But a URL like http://example.com/wp-content/plugins/ravatars/cache/eedf4ac9e08cd39ad.png will give a custom 404 page instead of displaying the image. We have carefully gone over file and directory permissions and .htaccess files and were unable to find anything that would cause the 404.
So far 3 people have reported the problem and they are all on 2.5.1. I am also running 2.5.1 and everything works fine.
I'm pretty much out of ideas as to what could be causing this. Anyone have any ideas?
Plugin homepage with discussion of the problem: http://grok-code.com/7/ravatar-wordpress-plugin-for-randam-avatars/