FIND:

			if ( $sent_info['sent_items'] >= $board_config['max_sentbox_privmsgs'] )

REPLACE WITH:

			if ($board_config['max_sentbox_privmsgs'] && $sent_info['sent_items'] >= $board_config['max_sentbox_privmsgs'])

FIND:

 NOTE --- This is a partial match, the whole line on a fresh installation looks like this:
	$search_img = '<a href="' . $temp_url . '"><img src="' . $images['icon_search'] . '" alt="' . $lang['Search_user_posts'] . '" title="' . $lang['Search_user_posts'] . '" border="0" /></a>';

$search_img = '<a href="'

IN-LINE FIND:

. $lang['Search_user_posts']

IN-LINE REPLACE WITH:

. sprintf($lang['Search_user_posts'], $username_from)

IN-LINE FIND:

. $lang['Search_user_posts']

IN-LINE REPLACE WITH:

. sprintf($lang['Search_user_posts'], $username_from)

FIND:

 NOTE --- This is a partial match, the whole line on a fresh installation looks like this:
	$search = '<a href="' . $temp_url . '">' . $lang['Search_user_posts'] . '</a>';

$search = '<a href="'

IN-LINE FIND:

. $lang['Search_user_posts']

IN-LINE REPLACE WITH:

. sprintf($lang['Search_user_posts'], $username_from)

FIND:

			if ( $saved_info['savebox_items'] >= $board_config['max_savebox_privmsgs'] )

REPLACE WITH:

			if ($board_config['max_savebox_privmsgs'] && $saved_info['savebox_items'] >= $board_config['max_savebox_privmsgs'] )

FIND:

	if ( $submit )

BEFORE, ADD:

	if ($submit && $mode == 'edit')
	{
		$sql = 'SELECT privmsgs_from_userid
			FROM ' . PRIVMSGS_TABLE . '
			WHERE privmsgs_id = ' . (int) $privmsg_id . '
				AND privmsgs_from_userid = ' . $userdata['user_id'];

		if (!($result = $db->sql_query($sql)))
		{
			message_die(GENERAL_ERROR, "Could not obtain message details", "", __LINE__, __FILE__, $sql);
		}

		if (!($row = $db->sql_fetchrow($result)))
		{
			message_die(GENERAL_MESSAGE, $lang['No_such_post']);
		}
		$db->sql_freeresult($result);

		unset($row);
	}

FIND:

			$to_userdata = $db->sql_fetchrow($result);

REPLACE WITH:

			if (!($to_userdata = $db->sql_fetchrow($result)))
			{
				$error = TRUE;
				$error_msg = $lang['No_such_user'];
			}

FIND:

				if ( $inbox_info['inbox_items'] >= $board_config['max_inbox_privmsgs'] )

REPLACE WITH:

				if ($board_config['max_inbox_privmsgs'] && $inbox_info['inbox_items'] >= $board_config['max_inbox_privmsgs'])

FIND:

					'USERNAME' => $to_username, 

REPLACE WITH:

					'USERNAME' => stripslashes($to_username), 

FIND:

		if ( !empty($HTTP_GET_VARS[POST_USERS_URL]) )

FIND:

		}

		if ( $mode == 'edit' )

REPLACE WITH:

		}
		else if ( $mode == 'edit' )

FIND:

			$privmsg_subject = $privmsg_message = '';

REPLACE WITH:

			$privmsg_subject = $privmsg_message = $to_username = '';

FIND:

		'S_SIGNATURE_CHECKED' => ( $attach_sig ) ? ' checked="checked"' : '', 
		'S_NAMES_SELECT' => $user_names_select,

REPLACE WITH:

		'S_SIGNATURE_CHECKED' => ( $attach_sig ) ? ' checked="checked"' : '',