Index: app/helpers/application_helper.rb
===================================================================
--- app/helpers/application_helper.rb	(revision 14045)
+++ app/helpers/application_helper.rb	(working copy)
@@ -327,14 +327,17 @@
   # Renders the project quick-jump box
   def render_project_jump_box
     return unless User.current.logged?
-    projects = User.current.projects.active.select(:id, :name, :identifier, :lft, :rgt).to_a
+    projects = []
+    user_projects = User.current.projects.active.to_a
+    user_projects.each { |p| projects.concat(p.self_and_ancestors.select(:id, :name, :identifier, :lft, :rgt).to_a)}
+    projects.uniq!
     if projects.any?
       options =
         ("<option value=''>#{ l(:label_jump_to_a_project) }</option>" +
          '<option value="" disabled="disabled">---</option>').html_safe
 
       options << project_tree_options_for_select(projects, :selected => @project) do |p|
-        { :value => project_path(:id => p, :jump => current_menu_item) }
+        { :value => project_path(:id => p, :jump => current_menu_item), :disabled => user_projects.include?(p) ? nil : 'disabled' }
       end
 
       select_tag('project_quick_jump_box', options, :onchange => 'if (this.value != \'\') { window.location = this.value; }')