>>693
直してみました．

(function(){
function callback(event){
if(event.type == 'SSTabRestored'){
if(gBrowser.mTabs.length > 1
&& event.originalTarget.linkedBrowser.contentWindow.document.URL == 'about:blank')
gBrowser.removeTab(event.originalTarget);
if(!event.originalTarget.linkedBrowser.SSTabRestoring) return;
delete event.originalTarget.linkedBrowser.SSTabRestoring;
}

var tab = gBrowser.mTabs,max = tab.length;
for(var i = 0;i < max;++i){
if(tab[i] == event.originalTarget
|| tab[i].linkedBrowser.SSTabRestoring
|| tab[i].linkedBrowser.docShell.busyFlags
|| tab[i].linkedBrowser.contentWindow.document.URL != 'about:blank') continue;
gBrowser.removeTab(tab[i--]); --max;
}
}
gBrowser.tabContainer.addEventListener('TabOpen',callback,false);
gBrowser.tabContainer.addEventListener('SSTabRestored',callback,false);
gBrowser.tabContainer.addEventListener('SSTabRestoring',function(event){
event.originalTarget.linkedBrowser.SSTabRestoring = true; },false);
})();