Plesk 11 MySQL connection problem when specifying database

Question

I am having some connection problems with MySQL users when trying to connect directly to a database. This came up when trying to use mysqli_connect in PHP.

$dbc=mysqli_connect('127.0.0.1', 'test_user', 'test_password', 'test_database');

To verify that the user is setup correctly in MySQL; from the linux shell;

If I specify the database : mysql -h 127.0.0.1-u test_user -ptest_password test_database The connection fails

If I don't Specify the database: mysql -h 127.0.0.1 -u test_user -ptest_password
Connection Succeeds

Here is the OS and MySQL information

• mysql Ver 14.14 Distrib 5.1.61, for redhat-linux-gnu (i386) using readline 5.1
• CentOS release 6.3 (Final)
• Plesk 11 install
• MySQL is listening on all addresses

Using the Plesk Control Planel, I have created a user test_user that has access to a database test_database.

SHOW GRANTS FOR 'test_user'@'%'

Grants for test_user@%                                                                                   
GRANT USAGE ON *.* TO 'test_user'@'%' 
    IDENTIFIED BY PASSWORD '*0319BFCC3B30D01FD6CE82075F9A6AAC6E8E6570'
GRANT ALL PRIVILEGES ON `test\_database`.* TO 'test_user'@'%'

On another MySQL 5.1 server that was installed via yum on Centos 6, I am able to connect directly to the database

mysql -h 127.0.0.1 -u test_user -ptest123 test_database

The my.cnf file on both the plesk server and other server don't have any additional options other than the defaults.

Question:

What would prevent a user from connecting directly to his/her database in MySQL?

mysql -h 127.0.0.1 -u test_user -ptest123 test_database

as opposed to

mysql -h 127.0.0.1 -u test_user -ptest123