Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2a1pre) Gecko/20081214 Minefield/3.2a1pre - Build ID: 20081214020626 Reproducible: Always Steps to Reproduce: 1. Add the following to <yourprofile>/chrome/userChrome.css (creating the file if it doesn't exist): /* * define distinctive backgrounds for tabs */ /* white for unread tabs */ .tabbrowser-tabs *|tab:not([selected]) { background-color: white !important } /* dark red for non-current tabs at mouseover */ .tabbrowser-tabs *|tab:hover { background-color: #C00 !important } /* bright cyan for current tab */ .tabbrowser-tabs *|tab[selected=true] { background-color: #0FF !important } /* bright yellow for current tab at mouseover */ .tabbrowser-tabs *|tab[selected=true]:hover { background-color: yellow !important } /* other tabs (read but not current) retain the BG color in the theme */ 2. Start (or restart) Firefox and have it open several tabs in the background (or from a multitab homepage or a multitab session) 3. Drag the last tab to first position. Actual results: - At step 2, most tabs are white (unread), this is expected. - After step 3, all tabs become grey (read), showing that they have acquired a "selected" attribute. Expected results: Moving a tab should not modify the attributes of any other tab.