I've unsuccessfully tried a number of suggested fixes found on the forums - none seem to apply specifically.
I'm running WP 2.0.6. I've made the suggested changes to wp-includes/functions.php.
I'm using this Ordered list plugin for Feedburner feed redirection (currently deactivated): http://orderedlist.com/wordpress-plugins/feedburner-plugin/
The only .htaccess changes I'm using are at the root level and serve to redirect domain.com to http://www.domain.com.
I've tried deactivating and reactivating the plugin, reuploading the various feed php files and I've tried some changes to .htaccess. I haven't be able to resolve this problem.
These feeds generate fine:
These don't work at all (generate 500 errors):
At this point, I just want to get the feeds working properly, and then I want to redirect them to feedburner.
Any help would be most appreciated...