Hi, I have a Toshiba 750GB external hard drive that I'm trying to use as a back up drive. When I plug it into my MacBook Pro (bought it maybe 2 weeks ago), it won't mount in the finder or the disk utility. If I plug the hard drive in to any other computer, it mounts no problem. Just not this one. I tried booting into safe mood and then restarting, I checked the permissions in my finder and it should be visible, I looked for it in disk utility but it doesn't show up there. It even shows up in my old MacBook Pro from 2009 which is also running Lion. Just not this one. Please help!!! Updated: Weirdly enough, it shows up in my system profiler. But nowhere else.