I don’t know how or why, but the gremlims seem to be playing with the comments. I’m assuming it’s some kind of wordpress.com problem. Comments will sometimes appear under one post, then another. I think each time a post is loaded, the comments are randomly allocated.
Not to mention, confusing.
So, if you think you’ve commented on a post, you probably have – it just may appear elsewhere!
I’ll try and find somewhere at wordpress.com to raise the issue, but that will have to wait until later as I have to go into town shortly.