I also had this problem. It went away when I granted the MySQL user all privileges. This means that the instructions on this page are incorrect:
http://www.osticket.com/wiki/Installation(http://www.osticket.com/wiki/Installation)
You will need one MySQL database with valid username, password and hostname handy during installation. The database username must have permission to CREATE, DROP and ALTER tables. If you are unsure whether you have these details or if your username has sufficient permissions, please consult your host or database admin before proceeding.
The user needs more than just CREATE,DROP,ALTER privileges.