diff --git a/browser/base/content/browser-feeds.js b/browser/base/content/browser-feeds.js
index 195d049b1e3..5b432ede2f9 100644
--- a/browser/base/content/browser-feeds.js
+++ b/browser/base/content/browser-feeds.js
@@ -118,15 +118,8 @@ var FeedHandler = {
     var haveFeeds = feeds && feeds.length > 0;
 
     var feedButton = document.getElementById("feed-button");
-    // Don't disable the button for customization mode. We check the URL
-    // here rather than the window's [customizing] attribute because they
-    // do not change at the same time, and the browser's feed info pertains
-    // to the selected page's browser, so using the location ensures
-    // this check is always correct:
-    let contentLoc = window.content && window.content.location.href;
-    let areCustomizing = contentLoc == "about:customizing";
     if (feedButton)
-      feedButton.disabled = !areCustomizing && !haveFeeds;
+      feedButton.disabled = !haveFeeds;
 
     if (!haveFeeds) {
       this._feedMenuitem.setAttribute("disabled", "true");
diff --git a/browser/components/customizableui/src/CustomizableWidgets.jsm b/browser/components/customizableui/src/CustomizableWidgets.jsm
index e0888406530..2bdf785807d 100644
--- a/browser/components/customizableui/src/CustomizableWidgets.jsm
+++ b/browser/components/customizableui/src/CustomizableWidgets.jsm
@@ -450,10 +450,9 @@ const CustomizableWidgets = [{
     },
     onCreated: function(node) {
       let win = node.ownerDocument.defaultView;
-      let browser = win.gBrowser.selectedBrowser;
-      let feeds = browser && browser.feeds && browser.feeds.length;
-      let contentURL = browser && browser.currentURI && browser.currentURI.spec;
-      if (contentURL != "about:customizing" && !feeds) {
+      let selectedBrowser = win.gBrowser.selectedBrowser;
+      let feeds = selectedBrowser && selectedBrowser.feeds;
+      if (!feeds || !feeds.length) {
         node.setAttribute("disabled", "true");
       }
     }
diff --git a/browser/components/customizableui/src/CustomizeMode.jsm b/browser/components/customizableui/src/CustomizeMode.jsm
index 7dd8c9dfcf7..2ab99657d64 100644
--- a/browser/components/customizableui/src/CustomizeMode.jsm
+++ b/browser/components/customizableui/src/CustomizeMode.jsm
@@ -413,11 +413,6 @@ CustomizeMode.prototype = {
       aNode.checked = false;
     }
 
-    if (aNode.disabled) {
-      wrapper.setAttribute("itemdisabled", "true");
-      aNode.disabled = false;
-    }
-
     if (aNode.hasAttribute("id")) {
       wrapper.setAttribute("id", "wrapper-" + aNode.getAttribute("id"));
     }
@@ -455,10 +450,6 @@ CustomizeMode.prototype = {
 
     let toolbarItem = aWrapper.firstChild;
 
-    if (aWrapper.hasAttribute("itemdisabled")) {
-      toolbarItem.disabled = true;
-    }
-
     if (aWrapper.hasAttribute("itemchecked")) {
       toolbarItem.checked = true;
     }
diff --git a/browser/themes/linux/browser.css b/browser/themes/linux/browser.css
index 9bc48b7ca61..8411f467033 100644
--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -645,7 +645,7 @@ toolbar > .customization-target > toolbarpaletteitem > #history-panelmenu {
 #print-button {
   list-style-image: url("moz-icon://stock/gtk-print?size=toolbar");
 }
-#print-button[disabled="true"] {
+:not(toolbarpaletteitem) > #print-button[disabled="true"] {
   list-style-image: url("moz-icon://stock/gtk-print?size=toolbar&state=disabled");
 }
 
@@ -660,21 +660,21 @@ toolbar > .customization-target > toolbarpaletteitem > #history-panelmenu {
 #cut-button {
   list-style-image: url("moz-icon://stock/gtk-cut?size=toolbar") !important;
 }
-#cut-button[disabled="true"] {
+:not(toolbarpaletteitem) > #edit-controls > #cut-button[disabled="true"] {
   list-style-image: url("moz-icon://stock/gtk-cut?size=toolbar&state=disabled") !important;
 }
 
 #copy-button {
   list-style-image: url("moz-icon://stock/gtk-copy?size=toolbar") !important;
 }
-#copy-button[disabled="true"] {
+:not(toolbarpaletteitem) > #edit-controls > #copy-button[disabled="true"] {
   list-style-image: url("moz-icon://stock/gtk-copy?size=toolbar&state=disabled") !important;
 }
 
 #paste-button {
   list-style-image: url("moz-icon://stock/gtk-paste?size=toolbar") !important;
 }
-#paste-button[disabled="true"] {
+:not(toolbarpaletteitem) > #edit-controls > #paste-button[disabled="true"] {
   list-style-image: url("moz-icon://stock/gtk-paste?size=toolbar&state=disabled") !important;
 }
 
@@ -702,7 +702,7 @@ toolbar > .customization-target > toolbarpaletteitem > #history-panelmenu {
   -moz-image-region: rect(0px 168px 24px 144px);
 }
 
-#feed-button[disabled] > .toolbarbutton-icon {
+:not(toolbarpaletteitem) > #feed-button[disabled] > .toolbarbutton-icon {
   opacity: .4;
 }
 
@@ -725,7 +725,7 @@ toolbar > .customization-target > toolbarpaletteitem > #history-panelmenu {
 #home-button.bookmark-item {
   list-style-image: url("moz-icon://stock/gtk-home?size=menu");
 }
-#home-button.bookmark-item[disabled="true"] {
+:not(toolbarpaletteitem) > #home-button.bookmark-item[disabled="true"] {
   list-style-image: url("moz-icon://stock/gtk-home?size=menu&state=disabled");
 }
 
@@ -1373,11 +1373,11 @@ toolbar[iconsize="small"] #bookmarks-menu-button[starred],
   -moz-image-region: rect(16px 144px 32px 128px);
 }
 
-#bookmarks-menu-button[disabled] > .toolbarbutton-icon,
-#bookmarks-menu-button[disabled] > .toolbarbutton-menu-dropmarker,
-#bookmarks-menu-button[disabled] > .toolbarbutton-menubutton-dropmarker,
-#bookmarks-menu-button[disabled] > .toolbarbutton-menubutton-button > .toolbarbutton-icon,
-#bookmarks-menu-button > .toolbarbutton-menubutton-button[disabled] > .toolbarbutton-icon {
+:not(toolbarpaletteitem) > #bookmarks-menu-button[disabled] > .toolbarbutton-icon,
+:not(toolbarpaletteitem) > #bookmarks-menu-button[disabled] > .toolbarbutton-menu-dropmarker,
+:not(toolbarpaletteitem) > #bookmarks-menu-button[disabled] > .toolbarbutton-menubutton-dropmarker,
+:not(toolbarpaletteitem) > #bookmarks-menu-button[disabled] > .toolbarbutton-menubutton-button > .toolbarbutton-icon,
+:not(toolbarpaletteitem) > #bookmarks-menu-button > .toolbarbutton-menubutton-button[disabled] > .toolbarbutton-icon {
   opacity: .4;
 }
 
diff --git a/browser/themes/osx/browser.css b/browser/themes/osx/browser.css
index 0cba21982ef..6c8e1249b38 100644
--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -450,20 +450,20 @@ toolbarbutton.bookmark-item > menupopup {
   margin: 2px;
 }
 
-.toolbarbutton-1[disabled="true"] > .toolbarbutton-icon,
-.toolbarbutton-1[disabled="true"] > .toolbarbutton-badge-container > .toolbarbutton-icon,
-.toolbarbutton-1 > .toolbarbutton-menubutton-button[disabled="true"] > .toolbarbutton-icon,
+#main-window:not([customizing]) .toolbarbutton-1[disabled="true"] > .toolbarbutton-icon,
+#main-window:not([customizing]) .toolbarbutton-1[disabled="true"] > .toolbarbutton-badge-container > .toolbarbutton-icon,
+#main-window:not([customizing]) .toolbarbutton-1 > .toolbarbutton-menubutton-button[disabled="true"] > .toolbarbutton-icon,
 #restore-button[disabled="true"] > .toolbarbutton-icon {
   opacity: .4;
 }
 
 @media (-moz-mac-lion-theme) {
-  .toolbarbutton-1[disabled="true"] > .toolbarbutton-icon,
-  .toolbarbutton-1[disabled="true"] > .toolbarbutton-badge-container > .toolbarbutton-icon,
-  .toolbarbutton-1 > .toolbarbutton-menubutton-button[disabled="true"] > .toolbarbutton-icon,
+  #main-window:not([customizing]) .toolbarbutton-1[disabled="true"] > .toolbarbutton-icon,
+  #main-window:not([customizing]) .toolbarbutton-1[disabled="true"] > .toolbarbutton-badge-container > .toolbarbutton-icon,
+  #main-window:not([customizing]) .toolbarbutton-1 > .toolbarbutton-menubutton-button[disabled="true"] > .toolbarbutton-icon,
   #restore-button[disabled="true"] > .toolbarbutton-icon,
-  .toolbarbutton-1[disabled="true"] > .toolbarbutton-menu-dropmarker,
-  .toolbarbutton-1[disabled="true"] > .toolbarbutton-menubutton-dropmarker,
+  #main-window:not([customizing]) .toolbarbutton-1[disabled="true"] > .toolbarbutton-menu-dropmarker,
+  #main-window:not([customizing]) .toolbarbutton-1[disabled="true"] > .toolbarbutton-menubutton-dropmarker,
   .toolbarbutton-1:not(:hover):-moz-window-inactive > .toolbarbutton-icon,
   .toolbarbutton-1:not(:hover):-moz-window-inactive > .toolbarbutton-badge-container > .toolbarbutton-icon,
   #restore-button:not(:hover):-moz-window-inactive > .toolbarbutton-icon,
@@ -473,9 +473,9 @@ toolbarbutton.bookmark-item > menupopup {
     opacity: .5;
   }
 
-  .toolbarbutton-1:-moz-window-inactive[disabled="true"] > .toolbarbutton-icon,
-  .toolbarbutton-1:-moz-window-inactive[disabled="true"] > .toolbarbutton-badge-container > .toolbarbutton-icon,
-  .toolbarbutton-1:-moz-window-inactive > .toolbarbutton-menubutton-button[disabled="true"] > .toolbarbutton-icon,
+  #main-window:not([customizing]) .toolbarbutton-1:-moz-window-inactive[disabled="true"] > .toolbarbutton-icon,
+  #main-window:not([customizing]) .toolbarbutton-1:-moz-window-inactive[disabled="true"] > .toolbarbutton-badge-container > .toolbarbutton-icon,
+  #main-window:not([customizing]) .toolbarbutton-1:-moz-window-inactive > .toolbarbutton-menubutton-button[disabled="true"] > .toolbarbutton-icon,
   #restore-button:-moz-window-inactive[disabled="true"] > .toolbarbutton-icon {
     opacity: .25;
   }
diff --git a/browser/themes/windows/browser.css b/browser/themes/windows/browser.css
index fa3cd7fc6b9..1adbdec2b86 100644
--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -343,11 +343,11 @@ menuitem.bookmark-item {
   list-style-image: url("chrome://browser/skin/Toolbar-inverted.png");
 }
 
-.toolbarbutton-1[disabled=true] > .toolbarbutton-icon,
-.toolbarbutton-1[disabled=true] > .toolbarbutton-menu-dropmarker,
-.toolbarbutton-1[disabled=true] > .toolbarbutton-menubutton-dropmarker,
-.toolbarbutton-1[disabled=true] > .toolbarbutton-menubutton-button > .toolbarbutton-icon,
-.toolbarbutton-1 > .toolbarbutton-menubutton-button[disabled] > .toolbarbutton-icon {
+#main-window:not([customizing]) .toolbarbutton-1[disabled=true] > .toolbarbutton-icon,
+#main-window:not([customizing]) .toolbarbutton-1[disabled=true] > .toolbarbutton-menu-dropmarker,
+#main-window:not([customizing]) .toolbarbutton-1[disabled=true] > .toolbarbutton-menubutton-dropmarker,
+#main-window:not([customizing]) .toolbarbutton-1[disabled=true] > .toolbarbutton-menubutton-button > .toolbarbutton-icon,
+#main-window:not([customizing]) .toolbarbutton-1 > .toolbarbutton-menubutton-button[disabled] > .toolbarbutton-icon,
   opacity: .4;
 }