I followed these instructions and still am having problems: (A) browser.link.open_newwindow - for links in Firefox tabs 3 = divert new window to a new tab (default) 2 = allow link to open a new window 1 = force new window into same tab (B) browser.link.open_newwindow.restriction - for links in Firefox tabs 0 = apply the setting under (A) to ALL new windows (even script windows) 2 = apply the setting under (A) to normal windows, but NOT to script windows with features (default) 1 = override the setting under (A) and always use new windows (C) browser.link.open_newwindow.override.external - for links in other programs -1 = apply the setting under (A) to external links (default) 3 = open external links in a new tab in the last active window 2 = open external links in a new window 1 = open external links in the last active tab replacing the current page