Odds are that your computer's BIOS is "freezing" the security features of the drive, to prevent viruses/trojans from using those features to lock you out of your own data.

To erase the drive, it has to be "unfrozen" first. Since the BIOS re-freezes it at every boot, that could be a problem.

But it isn't. Just boot up Linux (cdrom, whatever), and then unplug/replug the power for the SSD. It is now un-frozen, and can be erased. Note that the first command to set the passwd is not needed.

hdparm --security-erase NULL /dev/sdX

I do this quite frequently around here, even with notebook computers.

Edit: If it's still failing, use an Ubuntu CD rather than a nasty Fedora one. Fedora/Redhat is often crippled for useful stuff like this.

Cheers