diff --git a/app/assets/javascripts/tracks.js b/app/assets/javascripts/tracks.js
index 91301cc9..908eb6d5 100644
--- a/app/assets/javascripts/tracks.js
+++ b/app/assets/javascripts/tracks.js
@@ -588,7 +588,7 @@ var TodoItems = {
         $(document).on("click",'.item-container a.delete_dependency_button', function(evt){
             var predecessor_id=$(this).attr("x_predecessors_id");
             var ajax_options = default_ajax_options_for_scripts('DELETE', this.href, $(this).parents('.item-container'));
-            ajax_options.data << {predecessor: predecessor_id}
+            ajax_options.data["predecessor"] = predecessor_id
             $.ajax(ajax_options);
             return false;
         });
@@ -1245,7 +1245,7 @@ function setup_periodic_check(url_for_check, interval_in_sec, method) {
         function(){
             var settings = default_ajax_options_for_scripts( method ? method : "GET", url_for_check, null);
             if(typeof(AUTH_TOKEN) != 'undefined'){
-                settings.data << {authenticity_token: AUTH_TOKEN}
+                settings.data["authenticity_token"] = AUTH_TOKEN
             }
             $.ajax(settings);
         },
diff --git a/app/models/todo.rb b/app/models/todo.rb
index afb453e6..d91d8ee1 100644
--- a/app/models/todo.rb
+++ b/app/models/todo.rb
@@ -207,6 +207,7 @@ class Todo < ActiveRecord::Base
   def remove_predecessor(predecessor)
     self.predecessors.delete(predecessor)
     if self.predecessors.empty?
+      self.reload  # reload predecessors
       self.not_part_of_hidden_container? ? self.activate! : self.hide!
     else
       save!