diff --git a/phpBB/includes/acp/acp_database.php b/phpBB/includes/acp/acp_database.php
index 87c40ef78f..f09856b7fa 100644
--- a/phpBB/includes/acp/acp_database.php
+++ b/phpBB/includes/acp/acp_database.php
@@ -1494,7 +1494,7 @@ class acp_database
 					}
 					else
 					{
-						$row['rowdefault'] = $db->sql_fetchfield('rowdefault', 0, $def_res);
+						$row['rowdefault'] = $db->sql_fetchfield('rowdefault', false, $def_res);
 					}
 					$db->sql_freeresult($def_res);
 
diff --git a/phpBB/includes/functions_convert.php b/phpBB/includes/functions_convert.php
index ee97dcb3ab..6df29fc0f4 100644
--- a/phpBB/includes/functions_convert.php
+++ b/phpBB/includes/functions_convert.php
@@ -1647,7 +1647,7 @@ function add_bots()
 
 	$sql = 'SELECT group_id FROM ' . GROUPS_TABLE . " WHERE group_name = 'BOTS'";
 	$result = $db->sql_query($sql);
-	$group_id = (int) $db->sql_fetchfield('group_id', 0, $result);
+	$group_id = (int) $db->sql_fetchfield('group_id', false, $result);
 	$db->sql_freeresult($result);
 
 	if (!$group_id)
@@ -1656,11 +1656,12 @@ function add_bots()
 
 		$sql = 'SELECT group_id FROM ' . GROUPS_TABLE . " WHERE group_name = 'BOTS'";
 		$result = $db->sql_query($sql);
-		$group_id = (int) $db->sql_fetchfield('group_id', 0, $result);
+		$group_id = (int) $db->sql_fetchfield('group_id', false, $result);
 		$db->sql_freeresult($result);
 
 		if (!$group_id)
 		{
+			global $install;
 			$install->error($user->lang['CONV_ERROR_INCONSISTENT_GROUPS'], __LINE__, __FILE__);
 		}
 	}
diff --git a/phpBB/install/convertors/functions_phpbb20.php b/phpBB/install/convertors/functions_phpbb20.php
index eb660f84d0..fdde80c82c 100644
--- a/phpBB/install/convertors/functions_phpbb20.php
+++ b/phpBB/install/convertors/functions_phpbb20.php
@@ -76,6 +76,14 @@ function phpbb_insert_forums()
 		$db->sql_query("SET NAMES 'utf8'");
 	}
 
+	switch ($db->sql_layer)
+	{
+		case 'mssql':
+		case 'mssql_odbc':
+			$db->sql_query('SET IDENTITY_INSERT ' . FORUMS_TABLE . ' ON');
+		break;
+	}
+
 	$cats_added = array();
 	while ($row = $db->sql_fetchrow($result))
 	{
@@ -259,6 +267,14 @@ function phpbb_insert_forums()
 		$db->sql_query($sql);
 	}
 	$db->sql_freeresult($result);
+
+	switch ($db->sql_layer)
+	{
+		case 'mssql':
+		case 'mssql_odbc':
+			$db->sql_query('SET IDENTITY_INSERT ' . FORUMS_TABLE . ' OFF');
+		break;
+	}
 }
 
 /**