So just in case, you haven't ever noticed this phenomenon, I figure I'll just post the warning here. It's something I've known for some time, but just had myself reminded of it again this morning when I messed up.
If you read an Hitachi/HGST drive using the read by utility function of DE, then later switch to PIO or another mode, you must remember to power cycle the drive. Otherwise, all the data it'll be reading will be complete garbage. It'll act like it's reading data, and the sectors it reads will even look like data. But, it's not reading the correct sectors or possibly even just returning crap from RAM that's not the correct data.
I had a case reading by utility over the weekend. For some reason the computer rebooted and when I resumed I started to read by PIO. It seemed to be going quite well cleaning up some of the previously unread sectors, but then I realized that despite the computer having rebooted, the drive connected to PC-3000 never was power cycled. So now I'm having to re-read all the green boxes to make them orange... sigh.