At the moment i have set my powerbook off - writing random data 8 ways - because i am selling my mac, but the progress bar has stopped, i know it takes a long time but its been hours and as far as i can tell the bar has stayed at 2 pixels progress. This is the second time iv tried this with the same results - zeroing all data still works. i am running on a 667 g4 - 512mbram. Does it take days rather than hours? or is the progress bar not a good indication of progress? My mac also sleeps or at least turns off the screen - i tried to disable this in system preferences but to no avail, is this the source of my problems?