I've also experienced this on my A2. I did what you did several times, burned a few "coasters" until one time I had to leave the room for a while while it was "loading". After about 5 minutes (I didn't time it, but it seemed like forever) the question to update came up on the screen, and went smoothly from that point.
I had to do the shutdown and eject manually a few times because the noise made it sound it was going to break the laser drive, but I found I should have let it run. Apparently it is reading the whole upload before it displays the update message.
Give it a try. There was no damage done, and the player works perfectly.