Q:

Mysql 5.5 - Can't connect a user but root - ERROR 1045 (28000)

Issue
I've setup a PC with Ubuntu 13.10, installed mysql-server-5.5.35 and phpmyadmin-4.4.0.9-1.
With phpmyadmin I created the users ''jeby6372'' & ''internal'', set a password and read/write/insert/delete global privileges for each of them.
I can't connect users but root against the Mysql server.
Feedback
jeby6372@mercure:~$ mysql --version
mysql  Ver 14.14 Distrib 5.5.35, for debian-linux-gnu (x86_64) using readline 6.2

Connecting under root:
jeby6372@mercure:~$ mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 123
Server version: 5.5.35-0ubuntu0.13.10.2 (Ubuntu)

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

Connecting another user :
jeby6372@mercure:~$ mysql -u jeby6372 -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'jeby6372'@'localhost' (using password: YES)

The problem is the same with the internal user
here is a snapshot of my privileges configuration thru the phpmyadmin view:

As I created users thru the phpmyadmin, it may bug while updating passwords in the mysql database so I ran under MySql root:
mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> SET PASSWORD FOR 'jeby6372'@'localhost' = PASSWORD('mypassword');ERROR 1133 (42000): Can't find any matching row in the user table
mysql> SET PASSWORD FOR 'jeby6372'@'%' = PASSWORD('alpha1237');
Query OK, 0 rows affected (0.00 sec)

mysql> quit

Any idea ?
I've the same configuration on other servers that runs Mysql 5.5.35 on Ubuntu 12.04 and they work fine. 
Any suggestion ?
thanks for your help. 

A:

% does not include localhost. When connecting via sockets (or named pipes on Windows), the host is localhost; with TCP/IP connections that same host is referred to by 127.0.0.1.
So in your case, it's likely that the connection type is socket and therefore jeby6372@% doesn't match the connection attempt. This is the same reason the default MySQL installation comes with root@localhost and root@127.0.0.1; they're different connection types.
See #1044 - Access denied for user 'someuser'@'localhost' to database 'somedb' and https://dev.mysql.com/doc/refman/5.1/en/account-names.html
Hope that clears it up for you. 

