Whats the difference between information_schema.user_privileges and mysql.user?
INFORMATION_SCHEMA provides access to database metadata, information about the MySQL server such as the name of a database or table, the data type of a column, or access privileges. Other terms that are sometimes used for this information are data dictionary and system catalog.


Source - http://dev.mysql.com/doc/refman/5.5/en/information-schema.html

You should be taking at the proper commands for modifying accounts and flush PRIVILEGES to reload the PRIVILEGES.


http://dev.mysql.com/doc/refman/5.5/en/account-management-sql.html
http://dev.mysql.com/doc/refman/5.5/en/flush.html