You say, "Ive tried a number of times but keep getting the same error message". It's not clear whether you're reloading the backup in between attempts.
If you are and you're still getting this message, the next step is do delete and recreate the database before reloading the backup. Reloading a backup will replace the values in existing tables - but will NOT delete tables created when updating to 4.6.2, which is a possible cause for your error.
To delete and recreate the database, and assuming the database name is
DROP DATABASE myorg_civicrm;
Then create a blank database with:
CREATE DATABASE myorg_civicrm;
So long as the new blank database shares the same name as the deleted database, your MySQL user will have the same permissions on the new database - so just reload your dumped tables and try again!