Error:
Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'www-data'@'localhost' (using password: NO) in /home/user/public_html/library/database/database.php on line 16
Error: Could not make a database connection using @
Update:
I think I may have found the answer

The really strange and curious thing is----I've been playing with Zencart at the same time. Reinstalled it many times BEFORE I created the www-data mysql user and it installed perfectly everytime. Is there possibly something odd in the Opencart install config that causes this error on debian based systems? I don't know enough about it to tell but I can say it has been a frustrating experience.
Update 2:
Well it seems I may have spoken too soon. The successful install above was on the Mint partition. I tried last night to reinstall on the Kubuntu partition after taking the above steps and I'm getting the same error. Both are running identical Apache2, Mysql, PHP5 servers. If I were to try reinstalling on the Mint partition right now I'll bet it wouldn't work. I don't get it. It seemed like Mysql Administrator was acting a little squirrly so I tried adding the www-data user with both phpmyadmin and with Webmin just to be sure. Maybe there is a bug with mysql and the add user process or something.
I'm at my wits end with this but at least I have a successful install of Opencart I can play with
