I want to disable all SSL functions so i comment the Certificate_Name line in ioFTPD.ini.
Although when i m trying to log in my site i have a 504 error (504 Auth %s unsupported)
If you disable SSL for some strange reason you can no longer connect to your site using SSL.
In your client (typically FlashFXP, but the program that is showing you the auth unsupported error) disable SSL for your site.