eelixduppy - 11:37 pm on May 7, 2011 (gmt 0)
Hello and Welcome to WebmasterWorld!
Assuming you are using the correct host, username, and password, then my second guess would be that you are using an older mysql library that would require to use an older version of the MySQL passwords. If you can run a query in your database, try doing the following as root (or equivalent):
Password = OLD_PASSWORD('dbpw')
Host = 'localhost'
AND User = 'mydbusername';
And then flush the privileges: