I noticed something...
Downloaded latest DiscWizard (build 5077), and had the same problem (error E000101F4), my new Seagate (ST3750840AS) wasn't found, when I tried to use full version with USB etc. support. BUT, the other version without USB support found my disk, and I was able to backup partition C to partition D .
But, what's more important, I noticed that changing SATA Configuration on my new Asus P5Q-E made also the Full version to work! By default, SATA Configuration is "Enhanced", but changing it to "Compatible" made the Full version to work.
By the way, bios version on my motherboard is very old (0605 from 06/03/08) but before updating the bios I don't know if it affects to this problem.
Hope this could help you, DiscWizard is a great program when it's working !