First off all, hello from a new user!

Well, I´m trying to login in my db but when I try to conect with one user created by:
GRANT SELECT ON mdb1.* TO USER@"%" IDENTIFIED BY 'U'
the conection don´t work out. ERROR 1045. Doe´s somebody knows why?

Thank´s for your attention,
Rafael.

PS: sorry for my bad english.

Did you use
FLUSH PRIVILEGES
after creating the new user?

Yes, I did. Take a look on the prompt execution

mysql> GRANT SELECT, INSERT, DELETE, UPDATE ON mdb1.* TO KHD001@"%" IDENTIFIED BY 'KHD001';
Query OK, 0 rows affected (0.06 sec)

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.03 sec)

mysql> exit
Bye

C:\mysql\bin>mysql -u KHD001 -p
Enter password: ******
ERROR 1045 (28000): Access denied for user: 'KHD001'@'localhost' (Using password: YES)

Is there some mistake on my procedure?

Thank´s

Well, i've installed the msql control center and finally solved my problem..... I realised that all user's created with "%". So all user'ss host's are localhost. This is a temporary solution.
Does somebody know´s what´s wrong on
Grant .... to user@"%" ?
Thank's again,
Rafael.

Well, i've installed the msql control center and finally solved my problem..... I realized that all user's created with "%". So all user'ss host's are localhost. This is a temporary solution.
Does somebody know´s what´s wrong on
Grant .... to user@"%" ?
Thank's again,
Rafael.

It's because how MySql read the privilege table

When you connect to mysql
Mysql read your username, password and host

So if your are on the server your host is localhost

Mysql will list user with localhost and will find a default user with no privilege
and will chose it

So to enable connection with % on localhost you will need to delete this user

DELETE FROM user WHERE username = '' and HOST = 'localhost'