diff --git a/4chan_x.user.js b/4chan_x.user.js
index 9decc1631..c16294798 100644
--- a/4chan_x.user.js
+++ b/4chan_x.user.js
@@ -1001,6 +1001,12 @@
       }
       $.bind($('textarea[name=flavors]', dialog), 'change', $.cb.value);
       $.bind($('input[name=time]', dialog), 'keyup', options.cb.time);
+      /*
+          https://bugzilla.mozilla.org/show_bug.cgi?id=579776
+          position:fixed and position:absolute shouldn't turn display:-moz-box into display:block
+      
+          to harmonize, position:fixed and display:-moz-box have to be set on different elements.
+          */
       overlay = $.el('div', {
         id: 'overlay'
       });
diff --git a/script.coffee b/script.coffee
index 1ac6f577a..6095ff4b5 100644
--- a/script.coffee
+++ b/script.coffee
@@ -783,6 +783,12 @@ options =
     $.bind $('textarea[name=flavors]', dialog), 'change', $.cb.value
     $.bind $('input[name=time]', dialog), 'keyup', options.cb.time
 
+    ###
+    https://bugzilla.mozilla.org/show_bug.cgi?id=579776
+    position:fixed and position:absolute shouldn't turn display:-moz-box into display:block
+
+    to harmonize, position:fixed and display:-moz-box have to be set on different elements.
+    ###
     overlay = $.el 'div', id: 'overlay'
     $.append overlay, dialog
     $.append d.body, overlay