(I've just spent 1/2 hour deleting 32 of the 33 copies of my previous post).
Maybe I do need a better client than the web interface.
Oh, the irony. This apology just got posted a whole bunch of times too. I definitely only hit the post button once. My guess is Mozilla isn't getting an ACK for whatever reason, and is re-posting the data. Maybe LJ should have a (hidden) unique identifier on each post form to work-around the problem?