I've been struggling to understand what's going on with that for a day now. Looking through the code, and searching the support pages here. Finally it hit me when I found a year old topic on a isimilar problem that was claimed to be fixed.
So, the problem is that Comments RSS 2.0 feed show up as if there are no comments there. So I see the correct header with a few lines between <channel></channel>, the last of which is <generator> statement. No <item> statements (which are the actual comments) are present.
The comments of course are there. Moreover, I add few more just to make a bunch of them. It does not help, the system ignores the comments, and does not give the comments feed.
Comments RSS feed for all comments works just fine, as well as Entries RSS feed. It's just Comments RSS feed for a specific entry (post) does not work at all. That really had driven me crazy.
Now, after reading that year old topic I did the following: I clicked the 'Edit' link on my entry, and without doing anything there hit "Save'. That was all the system needed to give me the Comments RSS feed for that entry back. I've became a happy user of the feed.
The entry was couple of weeks old, and I've started to play with the feeds just now, adding new comments to those entries that were still open for comments/trackbacks/pingbacks.
So it appears that there is still a bug in WP 1.5.2 regarding Comments RSS feed for specific entry that is related to some timestamps. In particular, it appears there is someting like "last modification" timestamp that god updated when I re-saved my entry.
You can try add comments to other entries on my test blog setup at test blog. Entries "test 11" and "test 12" are those I've been playing with. Entries with lower numbers should do fine for the purposes of this test.
Does anyone knows of this problem? Is a fix in the works? Is is there something I don't understand here and this is the way it's supposed to work?
I would appreciate a clear explanation. Thank you.