A weird character in Jafer’s pingback title (or site title, actually) messed with my comment feed, so I decided to exclude pingbacks (as I won’t allow trackbacks) from my comments feed. I tweaked wp-commentsrss2.php file (found in the root WP folder), around lines 36 and 44:

AND $wpdb->comments.comment_approved = ‘1’ AND $wpdb->comments.comment_type != ‘pingback’

Comments are of type ” (null) and trackbacks are ‘trackback’, so I think putting comment_type = ” would work as well and you wouldn’t have to put a != (not equals) for both pingbacks and trackbacks.

[edit: May 9] That was a short-lived hack. WP1.5.1. solves the problem with odd characters causing grief for RSS feed readers [/edit]