Ok, I have an update on this problem and I hope at this point that it’s ironed out on my systems. I also have a MacBook Air (Early 2012) and I decided to see if the same thing happens on that machine so I hooked it up and after drive boot up I immediately began doing the same things on it to see how it reacted. Turns out that when connected to the MBAir it didn’t act up at all. I pondered on this and realized that the drive hadn’t had a chance to sleep yet, so decided to do the same thing on the iMac again but this time on the iMac. Switched it over to that machine and as soon as I heard the drive boot up completely I put it through the same test, and nothing happened. I believe now that the drive sometimes has difficulty coming out of sleep or something like that. So at the very least if I have to, I’ll set it up in El Capitan to keep the drive awake and the problem “Should be solved”, at least it will be for me. So, if I’m correct and I have no other problems, I consider this problem, for me, is solved. Obviously if I have to come back for more posting, I was wrong. Thanks for your help Trancer. I’m still not sure exactly what you meant in your post as I don’t think that iMacs even have BIOS. At least I’ve never heard of one having BIOS. Appreciate your time though.