Same Document Reference

Okay, so I’ve converted my WordPress install to use Atom 1.0 and (I think) made using it as the default1, but I’ve got one warning left that I just don’t get:

line 8, column 86: Same-document reference: http://www.symphonious.net/2006/08/13/those-who-still-need-classic/ [help]

... /08/13/those-who-still-need-classic/" />

Now I get that the two URLs are pointing to the same place, but why exactly is this a problem and what URL am I supposed to put in there? Should I just make up a new base URL so that it’s clearly not the same document? The URL is absolute so the xml:base shouldn’t affect it.

It would be really nice if the help pages for the validator actually explained why it was a problem rather than just what the problem is, at least for warnings.

1 – existing subscribers aren't being redirected – but you can resubscribe to the Atom feed if for some reason you feel it's superior.↩