diff --git a/www/kanban/inner.js b/www/kanban/inner.js
index 8344a4b26..e9c4e30b8 100644
--- a/www/kanban/inner.js
+++ b/www/kanban/inner.js
@@ -145,7 +145,7 @@ define([
     };
     var _updateBoardsThrottle = Util.throttle(_updateBoards, 1000);
     var updateBoards = function (framework, kanban, boards) {
-        if ((now() - _lastUpdate) > 5000) {
+        if ((now() - _lastUpdate) > 5000 || framework.isLocked()) {
             _updateBoards(framework, kanban, boards);
             return;
         }
@@ -1207,8 +1207,17 @@ define([
             var items = boards.items || {};
             var data = boards.data || {};
             var list = boards.list || [];
+
+            // Remove duplicate boards
+            list = boards.list = Util.deduplicateString(list);
+
             Object.keys(data).forEach(function (id) {
-                if (list.indexOf(Number(id)) === -1) { delete data[id]; }
+                if (list.indexOf(Number(id)) === -1) {
+                    list.push(Number(id));
+                }
+                // Remove duplicate items
+                var b = data[id];
+                b.item = Util.deduplicateString(b.item || []);
             });
             Object.keys(items).forEach(function (eid) {
                 var exists = Object.keys(data).some(function (id) {
diff --git a/www/kanban/jkanban_cp.js b/www/kanban/jkanban_cp.js
index 56dcfaa60..742fbc379 100644
--- a/www/kanban/jkanban_cp.js
+++ b/www/kanban/jkanban_cp.js
@@ -299,7 +299,9 @@ define([
                         // Move to trash?
                         if (target.classList.contains('kanban-trash')) {
                             list.splice(index1, 1);
-                            delete self.options.boards.data[id];
+                            if (list.indexOf(id) === -1) {
+                                delete self.options.boards.data[id];
+                            }
                             self.onChange();
                             return;
                         }
@@ -444,6 +446,14 @@ define([
             });
             return res;
         };
+        this.checkItem = function (eid) {
+            var boards = self.options.boards;
+            var data = boards.data || {};
+            var exists = Object.keys(data).some(function (id) {
+                return (data[id].item || []).indexOf(Number(eid)) !== -1;
+            });
+            return exists;
+        };
         this.moveItem = function (eid, board, pos) {
             var boards = self.options.boards;
             var same = -1;
@@ -453,11 +463,13 @@ define([
                 obj.board.item.splice(obj.pos, 1);
                 if (obj.board === board) { same = obj.pos; }
             });
-            // If it's a deletion, remove the item data
+            // If it's a deletion and not a duplicate, remove the item data
             if (!board) {
-                delete boards.items[eid];
-                delete self.cache[eid];
-                removeUnusedTags(boards);
+                if (!self.checkItem(eid)) {
+                    delete boards.items[eid];
+                    delete self.cache[eid];
+                    removeUnusedTags(boards);
+                }
                 self.options.refresh();
                 return;
             }