diff --git a/app/controllers/todos_controller.rb b/app/controllers/todos_controller.rb
index de6e283e..71d22346 100644
--- a/app/controllers/todos_controller.rb
+++ b/app/controllers/todos_controller.rb
@@ -144,19 +144,25 @@ class TodosController < ApplicationController
     
     if @todo.completed?
       logger.debug "completed #{@todo.description}"
-      # A todo was completed - check for pending todos
+      # A todo was completed - check for pending todos to activate
+      @pending_to_activate = []
       @todo.successors.each do |t|
         if t.uncompleted_predecessors.empty? # Activate pending todos
           logger.debug "activated #{t.description}"
           t.activate!
+          @pending_to_activate << t
         end
       end
     else
-      # Block todos for undone actions - (it does no harm if they are already pending)
+      # Block active successors for undone action
+      @active_to_block = []
       logger.debug "undid #{@todo.description}"
       @todo.successors.each do |t|
-        logger.debug "blocked #{t.description}"
-        t.block!
+        if t.state == 'active'
+          logger.debug "blocked #{t.description}"
+          t.block!
+          @active_to_block << t
+        end
       end
     end
     
diff --git a/app/helpers/todos_helper.rb b/app/helpers/todos_helper.rb
index b39d5674..cfd1dbf8 100644
--- a/app/helpers/todos_helper.rb
+++ b/app/helpers/todos_helper.rb
@@ -203,7 +203,7 @@ module TodosHelper
   def item_container_id (todo)
     if source_view_is :project
       return "p#{todo.project_id}items" if todo.active?
-      return "tickler" if todo.deferred?
+      return "tickler" if todo.deferred? or todo.pending?
     end
     return "c#{todo.context_id}items"
   end
diff --git a/app/views/todos/toggle_check.js.rjs b/app/views/todos/toggle_check.js.rjs
index 5f9e2734..92289b16 100644
--- a/app/views/todos/toggle_check.js.rjs
+++ b/app/views/todos/toggle_check.js.rjs
@@ -8,9 +8,15 @@ if @saved
       page.insert_html :top, "completed_containeritems", :partial => 'todos/todo', :locals => { :todo => @todo, :parent_container_type => "completed" }
       page.visual_effect :highlight, dom_id(@todo, 'line'), {'startcolor' => "'#99ff99'"}
       page[empty_container_msg_div_id].show if @down_count == 0 && !empty_container_msg_div_id.nil?
-      page.show 'tickler-empty-nd' if source_view_is(:project) && @deferred_count == 0
+      page.show 'tickler-empty-nd' if source_view_is(:project) && @deferred_count == 0 && @pending_count == 0
       page.hide 'empty-d' # If we've checked something as done, completed items can't be empty
     end
+    # Activate pending todos that are successors of the completed
+    @pending_to_activate.each do |t|
+      logger.debug "#300: Removing #{t.description} from pending block and adding it to active"
+      page[t].remove
+      page.insert_html :bottom, item_container_id(t), :partial => 'todos/todo', :locals => { :todo => t, :parent_container_type => parent_container_type }
+    end
     
     # remove container if empty
     if @remaining_in_context == 0 && source_view_is(:todo)
@@ -44,6 +50,14 @@ if @saved
     page.show "empty-d" if @completed_count == 0
     page.show "c"+@todo.context.id.to_s
     page[empty_container_msg_div_id].hide unless empty_container_msg_div_id.nil? # If we've checked something as undone, incomplete items can't be empty
+    # If active todos are successors of the reactivated todo they will be blocked
+    @active_to_block.each do |t|
+      logger.debug "#300: Block #{t.description} that are a successor of #{@todo.description}"
+      page[t].remove # Remove it from active
+      # Insert it in deferred/pending block
+      logger.debug "Insert #{t.description} in deferred/pending block"
+      page.insert_html :bottom, item_container_id(t), :partial => 'todos/todo', :locals => { :todo => t, :parent_container_type => parent_container_type }
+    end
   end
   
   page.hide "status"
diff --git a/db/tracks-17-test.db b/db/tracks-17-test.db
new file mode 100644
index 00000000..3f79ee53
Binary files /dev/null and b/db/tracks-17-test.db differ