Forums | MacLife

I've got a Mac Pro, had it for just over a year now (its an Early 2008 model).  A couple of nights ago, I was copying a large amount of data from my 320GB Iomega eGo Helium (USB) drive to one of my hard drives.  It was about 100GB of data, so I left it plugged into the front of my Mac Pro, and turned off my LCD monitor (which has 4 USB ports, and its plugged into a port on the back of my Mac Pro) and went to bed.

When I came back to it in the morning, the file copy had aborted, saying I didn't have permission or something, and the drive was ejected.  I had to force restart Finder to get the copy window to go away.  I restarted the file copy, turned off the monitor, and left it alone.  Upon returning, the copy had again quit.  I tried for a third time, and left my monitor on so I could watch the process.  It completed with no problems.

Yesterday, I was getting ready to copy over more files.  On a whim, I decided to plug the drive in, and then turn off the monitor, as I was planning on managing the copy via my laptop in the other room.  When I logged into Desktop Sharing, the drive wasn't connected.  So I went back to my Pro, turned on the monitor, unplugged/replugged the drive, and decided to turn the monitor off and on again, in quick succession.  Doing so made the USB drive dismount.  I then tried leaving the monitor on, but unplugging the USB cord that connects the monitor to the Pro.  Again, the drive dismounted.

So, any ideas or previous experience with a USB device/port that dismounts if another USB device disconnects from a different port?