Hi Joe;
I solved the php problem a while back. I had to manually edit the iPlanet obj.conf file to correct some entries that were automatically inserted by the iPlanet Administration Server. I've got both enhydra director & php running now without a hitch so far.
Although I use openldap on Apache with php, I'm using the Netscape directory with the iPlanet server running php. I compiled the php source --with-ldap={path to ldap base install directory} and ldap calls work fine for me.
Depending on Linux distribution you're using, it may be tricky. I installed openldap from source & it all was under /usr/local.
phpinfo() should show the ldap enabled & api info if properly compiled & configured. No changes should be needed to php.ini, but do look at any notes regarding openldap library paths with php. Good luck!