Delete cached requests on error.

4chan_x.user.js

@@ -371,6 +371,9 @@
           },
           onabort: function() {
             return delete $.cache.requests[url];
+          },
+          onerror: function() {
+            return delete $.cache.requests[url];
           }
         }, {
           responseType: responseType

script.coffee

@@ -299,6 +299,7 @@ $.extend $,
       req = $.ajax url, {
         onload:  -> cb.call @ for cb in @callbacks
         onabort: -> delete $.cache.requests[url]
+        onerror: -> delete $.cache.requests[url]
       }, {
         responseType: responseType
       }