diff --git a/app/assets/javascripts/app/models/application_model.js.coffee b/app/assets/javascripts/app/models/application_model.js.coffee
index 6b764a589..d86ace5e4 100644
--- a/app/assets/javascripts/app/models/application_model.js.coffee
+++ b/app/assets/javascripts/app/models/application_model.js.coffee
@@ -1,4 +1,13 @@
 class App.Model extends Spine.Model
+  constructor: ->
+    super
+
+    # delete object from local storage on destroy
+    @bind( 'destroy', (e) ->
+      className = Object.getPrototypeOf(e).constructor.className
+      key = "collection::#{className}::#{e.id}"
+      App.Store.delete(key)
+    )
 
   displayName: ->
     return @name if @name
@@ -69,3 +78,4 @@ class App.Model extends Spine.Model
       model: @constructor,
       params: @,
     )
+
diff --git a/app/assets/javascripts/app/models/sla.js.coffee b/app/assets/javascripts/app/models/sla.js.coffee
index 81a51135c..7f50cf6fb 100644
--- a/app/assets/javascripts/app/models/sla.js.coffee
+++ b/app/assets/javascripts/app/models/sla.js.coffee
@@ -1,4 +1,4 @@
-class App.Sla extends Spine.Model
+class App.Sla extends App.Model
   @configure 'Sla', 'name', 'first_response_time', 'update_time', 'close_time', 'condition', 'data', 'active'
   @extend Spine.Model.Ajax
   @url: 'api/slas'
diff --git a/app/models/application_model.rb b/app/models/application_model.rb
index a3806a03b..e72b4c882 100644
--- a/app/models/application_model.rb
+++ b/app/models/application_model.rb
@@ -10,9 +10,11 @@ class ApplicationModel < ActiveRecord::Base
   after_update  :cache_delete
   after_destroy :cache_delete
 
+  @@import_class_list = ['Ticket', 'Ticket::Article', 'History', 'Ticket::State', 'Ticket::Priority', 'Group', 'User' ]
+
   # for import other objects, remove 'id'
   def self.attributes_protected_by_default
-    if Setting.get('import_mode')
+    if Setting.get('import_mode') && @@import_class_list.include?( self.name.to_s )
       ['type']
     else
       ['id','type']