Just FWIW. I am using Mozilla 1.5 (let us call it a bug and I fancy it is Mozilla's but just in case it is not):
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5) Gecko/20031007
when I am writing near the end of the textbox, if I press any button the markup appears BUT the text scrolls back to the top (although the cursor remains at its place. So I read the top again (although if I go on writing, then the text area scrolls down again to show the cursor). Yes, it is funny...
Not a complain, just a bug notification.
I like it more or less, but I find it cumbersone having to move back, deleting, etc...
BTW: I like the flower at the test page :)
Pedro.