Dunno, I use Acronis True Image V11 and I recently backed up all four Windows OS's from my 4 machines (Win 98; XP; Vista & 7) plus a couple of Linux installs from the machine with the swap out disk caddies.
All to an external 500Gb SATA disk in a dock.
It's always worked fine for me and I picked up the Acronis software FOC from some offer or other so I'm a happy bunny.
Last restore I done was when I mistakenly installed a Linux distro over my Win XP

forgot to swap out the disk caddy before install, doh