I have just upgraded to Tiger (OSX 10.4) and thought I would give the quicktags a shot. I had never tried in previous versions of Safari so I don’t know what the behavior was previously. However, when the browser check was disabled, the buttons appeared but did not function correctly. If I clicked blockquote, for example, several linebreaks would be entered and then the open-blockquote tag would appear. If I selected text and then clicked blockquote, several linebreaks would be added after the selected text and the open-blockquote tag would be added following the line-breaks and completely disregarding the selected text. So, I guess I will still be using Firefox to do most of my writing.
