valid. Probably a sage issue. I haven't yet used feedburner for my comments feed, not that important and i would need to edit my .htaccess file or write a plugin.
The tagboard sucks, too much spam and no one uses it.
#1 - What happened to you tagboard? I would have posted this there, but....
#2 - Do you have a feedburner feed for your comments too, or just the main feed? The WordPress feed for your comments for some reason does not indicate that there are new comments in the Sage reader.