Works fine in Fx16 Rated 5 out of 5 stars

Does everything I want it to. (Some people should go back and update their old "doesn't work in [version]" ratings.)

You DO, however, need to fix your toolbarbutton re:the toolbarpalette (as it is now, it can screw up the sizing of a toolbar and even all of the other buttons on that toolbar--correctable via CSS, of course, but one shouldn't have to).