I ran into a problem on a client site running cPanel. One our our web apps was spitting out the following error:
Script Error
Cannot connect to MySQL: Client does not support authentication protocol requested by server; consider upgrading MySQL client
A quick Google search returned the fix : http://geekswithblogs.net/TimH/archive/2005/10/31/58591.aspx
From inside MYSQL, Run the following on the affected DB:
SET PASSWORD FOR user@localhost = OLD_PASSWORD('replacemepasswd');