! PostgreSQL doesn't support unsigned ints...

other/install_2-1_postgresql.sql

@@ -2631,12 +2631,12 @@ CREATE SEQUENCE {$db_prefix}user_drafts_seq;
 
 CREATE TABLE {$db_prefix}user_drafts (
   id_draft int default nextval('{$db_prefix}user_drafts_seq'),
-  id_topic int unsigned NOT NULL default '0',
-  id_board smallint unsigned NOT NULL default '0',
-  id_reply int unsigned NOT NULL default '0',
+  id_topic int NOT NULL default '0',
+  id_board smallint NOT NULL default '0',
+  id_reply int NOT NULL default '0',
   type smallint NOT NULL default '0',
-  poster_time int unsigned NOT NULL default '0',
-  id_member int unsigned NOT NULL default '0',
+  poster_time int NOT NULL default '0',
+  id_member int NOT NULL default '0',
   subject varchar(255) NOT NULL default '',
   smileys_enabled smallint NOT NULL default '1',
   body text NOT NULL,