Start the QR by reloading the captcha to avoid browser cached captchas.

4chan_x.user.js

@@ -1247,6 +1247,7 @@
         if (this.src !== 'about:blank') return setTimeout(loadChecking, 500, this);
       });
       $.add(d.body, iframe);
+      window.location = 'javascript:void(Recaptcha.focus_response_field=function(){})';
       if (conf['Persistent QR']) {
         qr.dialog();
         if (conf['Auto Hide QR']) qr.hide();
@@ -1254,8 +1255,7 @@
       $.on(d, 'dragover', qr.dragOver);
       $.on(d, 'drop', qr.dropFile);
       $.on(d, 'dragstart', qr.drag);
-      $.on(d, 'dragend', qr.drag);
-      return window.location = 'javascript:void(Recaptcha.focus_response_field=function(){})';
+      return $.on(d, 'dragend', qr.drag);
     },
     node: function(root) {
       return $.on($('.quotejs + .quotejs', root), 'click', qr.quote);
@@ -1588,7 +1588,7 @@
           return _this.count(arr.length);
         });
         this.count($.get('captchas', []).length);
-        return this.load();
+        return this.reload();
       },
       save: function() {
         var captcha, captchas, response;

changelog

@@ -1,5 +1,6 @@
 master
 - Mayhem
+  Ensure fresh captcha on QR load.
   Fix unXXXifier on pages starting with not XXXed numbers.
   Update image limit notifier for /vg/.
 

script.coffee

@@ -912,6 +912,8 @@ qr =
     $.on iframe, 'load', -> unless @src is 'about:blank' then setTimeout loadChecking, 500, @
     $.add d.body, iframe
 
+    # Prevent original captcha input from being focused on reload.
+    window.location = 'javascript:void(Recaptcha.focus_response_field=function(){})'
     if conf['Persistent QR']
       qr.dialog()
       qr.hide() if conf['Auto Hide QR']
@@ -919,8 +921,6 @@ qr =
     $.on d, 'drop',      qr.dropFile
     $.on d, 'dragstart', qr.drag
     $.on d, 'dragend',   qr.drag
-    # prevent original captcha input from being focused on reload
-    window.location = 'javascript:void(Recaptcha.focus_response_field=function(){})'
 
   node: (root) ->
     $.on $('.quotejs + .quotejs', root), 'click', qr.quote
@@ -1187,7 +1187,8 @@ qr =
       $.on @challenge,      'DOMNodeInserted', => @load()
       $.sync 'captchas', (arr) => @count arr.length
       @count $.get('captchas', []).length
-      @load()
+      # start with an uncached captcha
+      @reload()
     save: ->
       return unless response = @input.value
       captchas = $.get 'captchas', []