Over at the Early Retirement Forum, for which I assist in maintaining the forum software, I've been adding RSS icons and "Add to [My Yahoo!, Google, Bloglines, My MSN, etc.]" icons and working on getting a sensible RSS link and info system laid out. I have a news fader/ticker item that lists some of the icons and points to more RSS feed info. After collecting a number of icons in the images directory I decided to make and rss subfolder and move the images there so as not to clutter up the site owner's images directory with RSS icons.
After moving the images I updated all my image links and made a mental note to check the log for 404 erros in the next day or two. The next day I checked, and one IP was creating three 404 errors every 30 seconds looking for the old image locations! Yikes! I tracked which user it was, and it's a user that I know uses RSS but is not destructive. But there were no RSS feed requests associated with the image requests, so my first conclusion that he's requesting RSS feeds to often was not correct. I made symlinks for the images in their original locations to stop the 404 errors and hopefully get the user agent, IE6 on WinXP, to cache the icons and quit requesting them.