Fix MySQL Password IssuesWhen upgrading to mySQL from version 4.0.x to 4.1.x, the format has changed
Some apps still will use the 4.0 client, and they can not decipher the 4.1 passwords. To get around this, you will need to change the passwords back to the old style of storage. Note: this apparently only applies when you are upgrading, it does not seem to matter if it is a new install as PHP and other apps will use the newer client versions.
To set the passwords back to the original style, issue the following command:
SET PASSWORD FOR username@localhost = OLD_PASSWORD('password');
Fix MySQL Password Issues