I format the drive, run the installer, it reboots, installs the remaining software, then when it reboots into the first run screen... it doesn't, instead booting into the computer I've used to make the drive. Now when I try to boot into the HDD there is no user directory and obviously can't run. I've tried this on two machines with three different hard drives, and two different installer discs. Is there an known issue with making 10.6 bootable HDDs? Or am I just really unlucky? Also, is it possible to make an external drive bootable with both Snow Leopard and Mavericks? Or would the 'firmware' (or whatever) from Mavericks cause Snow Leopard to stop working?