Unlocking the main FTP account does not unlock additional FTP accounts, additional accounts must be unlocked separately from the "AdditionalFTP Accounts" page.
To unlock FTP access for other packages, you need to enter the eXtend control panel for that respective package.
Login at http://www.comnethosting.com using the credentials of the FTP account you wish to unlock, you will then be presented with various options for unlocking that particular account. Alternatively, accounts can be unlocked individually from your main control panel.