I Cheesed It Up

Well, I've crawled my way back into the light, and right off the bat I've buggered something up. When you try to trackback an entry, it goes to my error page.
I recently took all my posts back to the non-category status, and no longer have categories, nor a category archive.
Perhaps one of the resident geniuses can 'splain to me what badness I've done and how I should put it right again?
Pretty please?
Oops, should have said... it's The Cheese Stands Alone, for those of y'all who don't know me. :)

PS... Oops, nevermind, entirely my bad... I've fixed it now.
But it was nice to have a chance to remind you what a trainwreck I am sometimes. Pixy, I found it just as you were telling me the solution.
Thanks.