Thanks to the very astute Levi, I have found and fixed a problem with my feeds. For some reason WordPress includes an XML declaration that FeedBurner can’t handle, so I had originally edited that. When I reinstalled WordPress recently, it overwrote the feed files I had edited with the incompatible ones. Levi called my attention to my broken feed, and it took me a few minutes to figure out what the problem was. As soon as I did, though, I edited all of my feeds by hand and got rid of that bad declaration. Poof! Problem solved, and my feed is up and running and happy again. If you haven’t already subscribed, there are some handy links to do so right on the burned feed itself.

Added: I figured I’d give LivePress another shot, and it synced perfectly. Yay!