I would add this line to the top of your 2.php file:
echo dirname($_SERVER["SCRIPT_FILENAME"]) . '/scripts/db.sql';
and see if that looks like a valid path to the file. My guess is there is some setting on your server that is changing the directory and that is making the script appear to be not found. Another fix could be putting the full absolute path to the db.sql file in that call as well.