Postnuke not displaying correctly, PHP, Oscommerce, MYSQL

PHP programming For some reason our postnuke site will no longer work the content is not displayed correctly, it was switched from one service provider to another and no longer works. It worked fine before. We would like it up and running. I still have access to the old account. Plus other work with our oscommerce site, (These extras would be paid above this contract, a price would be negotiated before the work would commence. We need someone on a on going basis with at least 3 years experience in Oscommerce and PHP, MYSQL