Hmmm... it seems that some of my sites gnarleyness, in this case the search engine friendly URL hack that is running, breaks some of the features on older posts.

If you are looking for a specific post and utilize the category links, just change the URL syntax from http://chrisjdavis.ath.cx/archives/cat/3 to http://chrisjdavis.ath.cx/archives?cat=3 then all the comments and pingback will work again, or you can use the sitemap feature which I wrote for this specific reason, which will allow you to forgo the above rewriting of URL's. I am going to look into repairing this in the next few days, once I have enough time to look at the archive hack code and find out what is going awry.