Drive Genius trouble

I used the "shred" function on Drive Genius to shred free space on my startup drive (booted from a firewire drive to be able to do this with "free space only" activated). I have done this many times before successfully. However, this time when I booted up on my internal startup drive to start working as normal, the disc was full! All the original data was intact (thank God!) but Drive Genius has taken up all the free space, obviously by writing "nothing" wich filled the whole drive (1 Tb). It's supposed to write over free space with "nothing" and leave the space available but this time somehow it filled up the drive...

Any help on this?

Best Regards

Peter from Sweden

That's a weird one. I'd ask the Drive Genius people: Data Recovery: Mac OS X File Recovery, Windows/Mac Hard Drive Data Recovery Software