--- a/src/ldt/ldt/ldt_utils/models.py	Wed May 15 10:05:17 2013 +0200
+++ b/src/ldt/ldt/ldt_utils/models.py	Mon May 20 18:02:37 2013 +0200
@@ -1,5 +1,8 @@
+from .events import post_project_save
 from django.conf import settings
-from django.contrib.auth.models import User, Group
+from django.contrib.auth import get_user_model
+from django.contrib.auth.models import Group
+from django.core.files.storage import default_storage
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 from guardian.shortcuts import assign, remove_perm, get_perms
@@ -8,13 +11,13 @@
     get_current_user)
 from ldt.security.manager import SafeManager
 from ldt.security.models import SafeModel
-from ldt.utils import url as url_utils
+from ldt.utils import generate_hash, url as url_utils
+from ldt.utils.web_url_management import get_web_url
+from shutil import move
 from sorl.thumbnail import ImageField
 from tagging.models import Tag
 from utils import (create_ldt, copy_ldt, create_empty_iri, update_iri, 
     generate_uuid)
-from ldt.utils import generate_hash 
-from ldt.utils.web_url_management import get_web_url
 import datetime
 import lxml.etree #@UnresolvedImport
 import mimetypes
@@ -22,10 +25,8 @@
 import re
 import tagging.fields
 import uuid
-from shutil import move
-from django.core.files.storage import default_storage
-from .events import post_project_save
 
+User = get_user_model()
 
 class Author(SafeModel):
 
@@ -63,7 +64,7 @@
     update_date = models.DateTimeField(auto_now=True, verbose_name=_('media.update_date'))
     videopath = models.CharField(max_length=1024, null=True, blank=True, verbose_name=_('media.videopath'))
     duration = models.IntegerField(null=True, blank=True, verbose_name=_('media.duration'))
-    creator = models.ForeignKey(User, blank=True, null=True, verbose_name=_('media.creator'))
+    creator = models.ForeignKey(settings.AUTH_USER_MODEL, blank=True, null=True, verbose_name=_('media.creator'))
     description = models.TextField(null=True, blank=True, verbose_name=_('description'))
     title = models.CharField(max_length=1024, null=True, blank=True, verbose_name=_('title'))
     src = models.CharField(max_length=1024, verbose_name=_('media.src'))