i clicked on my hard drive (maybe double clicked?) to upload a photo to my blog from it, it all of a sudden went 'poof' and disappeard. i immediately plugged it into my other iMac to be sure no data was lost. i then re-plugged it into my iMac and it doesn't come up in the finder anymore. the only time i see it is when i go to disk utility. how do i get it back on my finder screen without loosing ANY data? thanks for you help!!!