This is the last update we have in whm.
MySQL 3.x/4.x If you are having any problems with MySQL 4.x, you can now choose to downgrade to MySQL 3.x in tweak settings. (6.4.0 build 6 or later only)

here is our build

WHM 6.4.2
Cpanel 6.4.2-E28

cPanel.net Support Ticket Number: