It is rare when I manage to break my own blog. Like most people, I have managed to break my blog by doing truly stupid things like deleting the main template, for example, but I've never managed to break it by adding a plugin to Firefox, so this is the reason I mention it here: so no one else will do the same thing I did and then find themselves dead in the water for a couple days as a result.
The Sage-Too plugin -- an RSS blog and newsreader -- was the culprit. The strange thing is that adding this plugin not only destroyed my ability to publish blog entries using Firefox, but it also somehow interfered with my ability to publish blog entries from Safari! Not only that, but I could not edit an existing entry, nor could I save or publish a new entry or an edited blog entry, and in fact, the text boxes looked empty, making them impossible to edit.
I'll keep that in mind if I ever move to a Movable Type system.
If you're looking for a new feedreader, FeedDemon is pretty good. (It has a Mac equivalent, too, whose name escapes me.)
Ummmm.. Google Reader. You'll never look back.
thanks for the suggestions! i'll be looking in to them shortly.