From this post on the Ajax Developer's Journal site we learn that there has been an update to the Zend Core for Oracle - the addition of enhanced PL/SQL support and validation functionality for Oracle Database XE.

Zend Technologies, Inc., the PHP company, has announced an updated version of Zend Core for Oracle, which supports businesses using PHP for mission-critical Web applications by delivering a reliable, high performance, easy-to-install PHP development and production environment fully integrated with the Oracle Database 10g.The new release is validated with Oracle Database 10g Release 2, including the Oracle Database 10g Express Edition (Oracle Database XE).

In addition to validation of Oracle Database 10g Release 2, the update to Zend Core for Oracle has enhanced support for Oracle Procedural Language for SQL (PL/SQL) collection types, giving significantly improved performance. Developers can access PL/SQL directly from PHP in a single, fully integrated environment.

You can download this latest update directly from the Zend site