Index: src/django_gheat/gheat/management/commands/import_droidstumbler.py
===================================================================
--- src/django_gheat/gheat/management/commands/import_droidstumbler.py	(revision 9597)
+++ src/django_gheat/gheat/management/commands/import_droidstumbler.py	(revision 9598)
@@ -32,5 +32,6 @@
   cursor = connection.cursor()
   try:
-    sql = "INSERT INTO %s VALUES %s" % (sql_table, ','.join(sql_values))
+    # Make sure the special NULL is preserved
+    sql = "INSERT INTO %s VALUES %s" % (sql_table, ','.join(sql_values).replace("'NULL'",'NULL'))
     count = cursor.execute(sql)
     transaction.commit_unless_managed()