Find a solution for the problem appearing on the first click.

static/plugin_dbui/src/applinkedcombobox.js

@@ -42,7 +42,8 @@ App.form.LinkedComboBox = Ext.extend(Ext.form.ComboBox, {
      */	
     initComponent: function () {
 
-
+        this.lazyInit = false;
+        
         // configure a master combobox.
         // create a local store containing the values which can be used 
         // to filter the master store
@@ -73,6 +74,14 @@ App.form.LinkedComboBox = Ext.extend(Ext.form.ComboBox, {
         } else {
             this.store.on('datachanged', this.onDataChanged, this);
         }
+        
+        // logic to load the underlying view in the initialisation phase
+        // by mimicking the click by a user
+        // require by the filtering mechanism
+        this.on('render', function (combo) {
+            combo.onTriggerClick();
+            combo.collapse();
+        });
     },
 
     /**
@@ -115,6 +124,7 @@ App.form.LinkedComboBox = Ext.extend(Ext.form.ComboBox, {
      * the first value of the filtered store
      */
     onDataChanged: function () {
+        
         var value = this.store.getAt(0).get(this.displayField);
         this.setValue(value);
     }