Coming at you live from battery power for the first time ever!
I finally had total recall and remembered, as I just mentioned, why I always assumed it was a software issue. I had forgotten that over the years, but dug deep to figure it out.
I went into my video card control panel, an ATI Mobility Radeon x700, and stumbled upon some sort of battery optimizer that changes the computer's hardware settings to lengthen battery life. I figured maybe it was causing some glitch, so I turned it off and, to test it, pulled my AC cord. The screen went black again, bummer. I decided to restart without the plug in to take inventory of exactly what happens, and was amazed that my computer started! For the first time ever it was running on battery power! The computer must have needed restarted for that change to take effect.
The system and programs were still loading, but it was working without question. Until the little Notebook Hardware Control icon came up, and the screen went black again. My heart sunk, but then I realized the obvious, my computer HATES battery optimizing software! I rebooted on AC power, uninstalled Notebook Hardware Control, and here I write to you totally on battery power.
I can't believe it took me years to figure this out. I'd very rarely ever want to use my computer on battery power, so it never really bugged me much. It was just annoying for the plug to get bumped and force me to have to reboot, or worse, lose unsaved data. Thanks so much for all your help! It may seem like I figured it out on my own, but it was through all our discussions that I was able to identify the problem. Woo hoo!