upgrade to php5.1.5 from php5.0.4 error

[acidbox]

When I attempt to upgrade php from 5.0.4 to 5.1.5 using the unstable rpms, i get the following dependency error:

php-domxml is needed by (installed) psa-php4-configurator-1.0.0-rhel4.build80060329.02.noarch

This is a Plesk 8 RHEL4 box