Index: branches/5.1.x/install/install_schema.sql
===================================================================
diff -u -N -r13096 -r13961
--- branches/5.1.x/install/install_schema.sql	(.../install_schema.sql)	(revision 13096)
+++ branches/5.1.x/install/install_schema.sql	(.../install_schema.sql)	(revision 13961)
@@ -28,7 +28,7 @@
   Hits double(20,6) NOT NULL DEFAULT '0.000000',
   CachedRating varchar(10) DEFAULT '0',
   CachedVotesQty int(11) NOT NULL DEFAULT '0',
-  CreatedById int(11) NOT NULL DEFAULT '-1',
+  CreatedById int(11) DEFAULT NULL,
   Priority int(11) NOT NULL DEFAULT '0',
   `Status` tinyint(4) NOT NULL DEFAULT '2',
   EditorsPick tinyint(4) NOT NULL DEFAULT '0',
@@ -42,7 +42,7 @@
   HotItem tinyint(4) NOT NULL DEFAULT '2',
   Archived int(11) NOT NULL DEFAULT '0',
   Modified int(11) DEFAULT NULL,
-  ModifiedById int(11) NOT NULL DEFAULT '-1',
+  ModifiedById int(11) DEFAULT NULL,
   OrgId int(11) DEFAULT NULL,
   PRIMARY KEY (NewsId),
   UNIQUE KEY ResourceId (ResourceId),