the nice thing about the way things are (increasingly) set up in kmeleon is that you can have a unique toolbar that might not appeal to anyone else on earth... all it takes is a little configuring.
if you set up a togglepref macro for the preference "network.proxy.type" and toggle it between the values zero and one (for manual proxy settings) it should work... an example of how to do so is <a href="
http://kmeleon.sourceforge.net/docs/toggle.php">here</a>.
try it out and see how it works.
--- po