rMBP Hibernating when removing power cord

Hi there Guys,

Apologies if this has been posted/answered before, but Googling around I only found threads about how to change hibernation modes, or problems with MBP's not hibernating at all....mine is the opposite!

I have a 13" retina MBP, a few weeks old (i7 3.0GHz, 8GB, 512GB SSD), now running v10.8.4 but it did the same on v10.8.3 as well.

Using the Mac whilst connected to the mains power cord, all fine....if I then remove the power cord it'll be fine for 20-25secs, then black screens whilst it's hibernating (ie destaging to SSD)....really annoying when you're in the middle of doing something.

Likewise, if the Mac has already switched the screen off, I remove the power without waking it, then wake it when on battery, it does exactly the same 20-25secs later, and re-enters hibernation!

I've tried resetting the SMC, made no difference.

I'm in Hibernation Mode 3...I also have a 2009 15" MBP Core Duo system (also on 10.8.4), which doesn't behave this way, so don't think it's supposed to be working this way?

Any help gratefully received! If you need me to look in a log file somewhere, please just shout.

Thanks
Spencer.

 

Battery Health reported at 100% with only 12 charge cycles...the unit's only about a month old!

Use it predominantly on battery yes, but also on battery when on the train, in meetings, sitting on the sofa working/surfing (like now). I use it no differently from my 2009 MBP which after 4yrs of solid professional use (as opposed to just evenings "social" use) its got a battery health of ca.95% IIRC

 

Am pretty sure it's hibernating, insomuch that when it decides after 25secs to go to sleep, even when typing/surfing/general active use, the screen goes black (but still on), with keyboard backlighting still on, and the cursor arrow is visible while its (what I think is) de-staging the RAM to SSD, then when complete, the screen actually goes off, the k/b backlights go off and it then takes a good 5-10secs to wake it up again (ie while it re-writes the RAM contents back from SSD, I'm guessing)

WRT to the power settings:

On Power -->

Computer Sleep = Never, Display Sleep = 15min
HDD Sleep = yes
Wake for WiFi Access = yes
PowerNap = yes

On Battery -->

Computer Sleep = 10min, Display Sleep = 5min
HDD Sleep = yes
Dim display on battery = yes
PowerNap = no

No schedule settings used

Screensaver settings = 20mins, and requires PW immediately after sleep/ssaver begins (mandatory for work use)

Cheers
Spencer