diff --git a/themes/classic/global/mac/menulist.css b/themes/classic/global/mac/menulist.css
index 2bc348dd7f5..892291481f5 100644
--- a/themes/classic/global/mac/menulist.css
+++ b/themes/classic/global/mac/menulist.css
@@ -3,6 +3,7 @@
  * This style is fully scalable in 2 dimensions.  It supports menulists in
  * both active and disabled states, which includes 3 sets of sliced images.
  ********************************/
+@namespace html url("http://www.w3.org/1999/xhtml"); /* namespace for HTML elements */
 
   menulist {
     -moz-binding		  : url(chrome://global/skin/menulistBindings.xml#nine-slice-menulist);
@@ -247,7 +248,7 @@ menulist[editable="true"]
     padding             : 0px;
   }
    
-.menulist-editable-text 
+html|*.menulist-editable-text 
   {
     
     border                : none !important;
diff --git a/themes/classic/global/win/menulist.css b/themes/classic/global/win/menulist.css
index 5dc5455d85b..1a6f6d2a8f2 100644
--- a/themes/classic/global/win/menulist.css
+++ b/themes/classic/global/win/menulist.css
@@ -1,3 +1,5 @@
+@namespace html url("http://www.w3.org/1999/xhtml"); /* namespace for HTML elements */
+
 /* outer frame */
   menulist 
     {
@@ -141,7 +143,7 @@
  * Editable menulists (comboboxes) 
  */
   
-.menulist-editable-text 
+html|*.menulist-editable-text 
   {
     border                : none !important;
     margin                : 0px !important;
diff --git a/themes/modern/global/menulist.css b/themes/modern/global/menulist.css
index 6088e4cc3bf..8b0336c60e8 100644
--- a/themes/modern/global/menulist.css
+++ b/themes/modern/global/menulist.css
@@ -26,6 +26,7 @@
   ======================================================================= */
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
+@namespace html url("http://www.w3.org/1999/xhtml"); /* namespace for HTML elements */
 
 /* :::::nine slice menulist ::::::::::
    :: This is the default style used for all menulists.
@@ -282,7 +283,7 @@ menulist[editable="true"] {
   border: 1px solid #5D616E;
 }
 
-.menulist-editable-text {
+html|*.menulist-editable-text {
   border: none !important;
   margin: 0px !important;
   padding: 0px !important;