I just bought a MBP, and I am selling my old powerbook and want all the info off it. I have an external lacie drive that i have OSX installed on. So I booted off that in target mode on the old powerbook, so it was running the OS off the lacie. I want the internal hard drive erased. so i went to disc utility, and did 7pass erase utility, but it says "volume erase failed. unable to unmount disk." but im booting off the lacie, and i know i am trying to erase the internal HD..... please help!