I use TTC Security plugin (http://herselfswebtools.com/2008/06/wordpress-security-plugin-block-scrapers-hackers-and-more.html). I had been testing the feed of my site, managed by feedburner, with blocked user agents and now all I get is a cached page :(
I have tried everything from deleting the cache, plugin as well as setting $wp_cache_shutdown_gc = 1.
Nothing works ! You can try the feed here : http://feeds2.feedburner.com/LesAventuresDeTechiemaque