I'm prepping to do a clean install of Leopard. I used the lastest edition of Carbon Copy Cloner to clone my hard drive to an external Toshiba USB hard drive (here). It appears it successfully cloned. Here's the strange thing: I can boot off of this HDD when attached when starting up the computer, but when I boot off my normal internal hard drive I cannot access the external drive from within OS X at all. Plugged into the left USB port, I can hear it going "click, click, click," like it's trying to spin up and cannot. Using the right USB port, it spins up fine but nothing happens. No mount, nothing. Disk Utility does not show it at all regardless of which USB port it is plugged into. Why can I boot off of it to start with but can't access it otherwise? I have partitioned the external drive into two sectors, one 200GB for the bootable clone and the other the remainder to use as standard storage space. Both are HFS+, so obviously they should be recognized. What am I missing? Thanks for your help.