Computer Acts Like I Let the Battery Run Down

Question

When I put my MacBook Pro to sleep OR leave it to go to sleep on its own, often (but not always) it acts like I ran the battery down - in other words, I get the start-up sound (not the music but the little electronic movement sound) and the greyed screen with the line of white ovals at the center bottom which count up as the computer wakes itself up.
This problem began soon after I got my MacBook (almost 2 years) and has gotten worse. It used to be only occassional and was, of course, hard to replicate on demand. Now it's very often. (Every other day?) I took it into the MacStore before the year support was up and the girl looked at all sorts of stuff but couldn't find the problem. She made a few setting adjustments or whatever and said to see if it got better and, if not, to spend some time taking notes to see if I could better localize when it happens and if I still found nothing than to reinstall the OS X.
It was a little better for a bit it seemed, but built up to being more common again. It defintely happens when I use the computer on battery if I let it run down to anywhere about 23% or lower. But it also happens (often) when it's plugged in at my desk and I put it on sleep for the night, so at full battery.
Eventually I rebuilt without erasing, then - when still no improvement - I did a full erase and reinstall from Time Machine back-up (in case there's an answer there). I also upgraded to Mavericks. The problem was totally unaffected by the rebuilds or the upgrade. I have looked again at energy saving and see nothing unusual in my options. (Battery: Display to sleep after 5 minutes, computer to sleep after 10. Put hard disk to sleep when possible. Power adaptor: the same setting except 10min and 10 minutes.)
Any idea what the heck is going on?

Answer 1

Hi RobRZ -
So first of all, sorry for dragging my feet on doing this. I saw all the article chat about changing setting in terminal and presumed I was going to go in there and end up changing something. But in the end I jsut put in the first command ot check the hibernation mode and, well, it says "hibernate 3" - safe sleep.
So, that would indicate that my computer is already, according to Terminal, programmed to do something different than what it's actually doing. Right?
If it's a clue to what's happening: I tried soemthing different (again?I'm sure I'd done this before but didn't get consistent results) the last few days, unplugging my computer before I go to bed. Once it made the "electronic movement" (harddrive?) sound when I unplugged it, but woke right up in the morning. The last 2-3 nights I have unplugged it, to no computer noises, and it woke up just fine in the morning.
So, running the battery to below 20% causes it and, perhaps, leaving it plugged in when it's fully charged causes it?