Ok, the 'simplefeed' author seems to be a MySQL-only developer, so we have to patch even more

drupal/drupal.patch

@@ -330,7 +330,7 @@ Index: sites/all/modules/img_assist/img_assist_popup.js
 --- /dev/null	2008-05-02 21:08:21 +0200
 +++ sites/all/modules/img_assist/img_assist_popup.js	2008-05-02 21:05:56 +0200
 @@ -0,0 +1,20 @@
-+/* $Id: drupal.patch,v 1.22 2008/06/14 14:01:05 rse Exp $ */
++/* $Id: drupal.patch,v 1.23 2008/06/14 14:26:34 rse Exp $ */
 +
 +function launch_popup(nid, mw, mh) {
 +	var ox = mw;
@@ -703,6 +703,7 @@ Index: sites/all/modules/xmlcontent/xmlcontent.module
 -----------------------------------------------------------------------------
 
 Fix upgrading in "simplefeed" module if PostgreSQL is used.
+Fix modules as Drupal 6.2 does not provide db_num_rows() anymore.
 
 Index: sites/all/modules/simplefeed/simplefeed.install
 --- sites/all/modules/simplefeed/simplefeed.install.orig	2008-06-11 07:22:28 +0200
@@ -727,13 +728,9 @@ Index: sites/all/modules/simplefeed/simplefeed.install
    return $ret;
  }
  
------------------------------------------------------------------------------
-
-Fix modules as Drupal 6.2 does not provide db_num_rows() anymore.
-
 Index: sites/all/modules/simplefeed/simplefeed_item.install
 --- sites/all/modules/simplefeed/simplefeed_item.install.orig	2008-06-11 07:22:28 +0200
-+++ sites/all/modules/simplefeed/simplefeed_item.install	2008-06-14 15:49:19 +0200
++++ sites/all/modules/simplefeed/simplefeed_item.install	2008-06-14 16:23:01 +0200
 @@ -40,13 +40,15 @@
    // Fetch up to N feed items and update their iids to new schema
    $count = $_SESSION['simplefeed_item_update_2']['count'];
@@ -751,6 +748,27 @@ Index: sites/all/modules/simplefeed/simplefeed_item.install
      $_SESSION['simplefeed_item_update_2']['count'] += $limit;
      // Return progress (never return 100% here to ensure clean-up is still run last).
      return array('#finished' => $_SESSION['simplefeed_item_update_2']['vid'] / ($_SESSION['simplefeed_item_update_2']['max'] + 1));
+@@ -60,8 +62,18 @@
+ 
+ function simplefeed_item_update_3() {
+   $ret = array();
+-  $ret[] = update_sql("ALTER TABLE {simplefeed_feed_item} CHANGE url url text");
+-  $ret[] = update_sql("ALTER TABLE {simplefeed_feed_item} CHANGE iid iid varchar(32) NOT NULL");  
++  switch ($GLOBALS['db_type']) {
++    case 'mysql':
++    case 'mysqli':
++      $ret[] = update_sql("ALTER TABLE {simplefeed_feed_item} CHANGE url url text");
++      $ret[] = update_sql("ALTER TABLE {simplefeed_feed_item} CHANGE iid iid varchar(32) NOT NULL");  
++      break;
++    case 'pgsql':
++      $ret[] = update_sql("ALTER TABLE {simplefeed_feed_item} ALTER COLUMN url TYPE text");  
++      $ret[] = update_sql("ALTER TABLE {simplefeed_feed_item} ALTER COLUMN iid TYPE VARCHAR(32)");  
++      $ret[] = update_sql("ALTER TABLE {simplefeed_feed_item} ALTER COLUMN iid SET NOT NULL");  
++      break;
++  }
+   return $ret;
+ }
+ 
 Index: sites/all/modules/autologout/autologout.module
 --- sites/all/modules/autologout/autologout.module.orig	2008-03-14 21:05:41 +0100
 +++ sites/all/modules/autologout/autologout.module	2008-06-14 15:57:27 +0200