I made a slight error in my previous solution. on my add a comment function apparently I thought I didn't need the livequery plugin, but I was wrong. So you need to load the livequery plugin for jquery and then add this jQuery.livequery.run(); towards the end of the add_comment function. This statement causes the DOM to be reloaded and be seen by jquery for the new elements that were added with the load routine.
//add a comment function add_comment(CommentId) { new jQuery('#addcomment'+CommentId).hide().load('/comments/ add_comment/'+CommentId, {}, function() { jQuery(this).slideDown('fast'); } ); jQuery.livequery.run(); return false; } //add a comment end