Mysql Authentication problem

Hi I am having problems using php to access a Mysql database as an authecitcated user. Environment: Solaris 8, apache 1.3.28, php 4.3.1, mysql 3.23.43 My php scripts can connect to the test database using null user and password. However, when I attempt to connect from a php script as user foo password bar I get an "Access denied for user foo@localhost using password=YES". However, this user/password combo is acceptable to the mysql command line client. I assume php is talking to mysql because i can connect as an unauthenticated user to the test database, however when php tries to connect, from localhost, as a valid user, it is not authenticating. The user has both localhost and % host privileges in the mysql permission schema. Where do I look next? Cheers James