PHPMyAdmin reports a failed login, even though the database username appears correct.

[Igor]

This problem can occur when a username longer than 16 characters is used, due to the fact that Mysqld truncates any usernames longer than this length internally. As a result, if your database username was thisismyaccount17, when Mysqld authenticates that username against the stored password, it would think your username was Thisismyaccount1. Consequently, in order to resolve this problem, the solution would be to use a username that is less than 16 characters in length.