Site caching a php page?
Have you cleared cache yet? If not, go to the URL below to clear the sites cache. See if the error changes like you expected.


Drupal 6: /admin/settings/performance/drupal
Drupal 7: /admin/config/development/performance


It could also be that you changed the password of the SQL user that Drupal uses to operate, in which case you would need to update that information in /sites/yoursite/settings.php

What version of Drupal are you using?