it might not be.
i decided to roll back to 10.8.1 using time machine today (because this all started for me when i updated to 10.8.2 last week)
everything went fine, it restored, rebooted and then it suddendly happened again...
i'm very dissapointed to say that now my mac pro will not boot at all.
The glitchy fragmented pixels now show up at startup and i cannot even CMD+R, CMD+T or even Eject to do a fresh install of Snow Leopard...
my Mac Pro was working fine till i upgraded to Mountain Lion this month and the whole system has crashed and burned since i updated to 10.8.2.
this has destroyed me since i live in Greece and there isnt an Official Apple Store in this country.
I am probably looking at a couple of hundred euros Just to get it looked at and probably forced to buy new parts
for a mac that was working in tip top condition untill i upgrade to MT.
There are only Authorised Resellers here and all they care about is selling new macs and not helping people get their machine working without bleeding them dry.
And i dont want to get started on how behind i am on my work schedule because of the constant glitches and crashes i've had this month with Mountain Lion.
This is unacceptable and i need help.
this whole affair with MT has put my job and career at risk.
Hm. The earliest Mac Pro that can run Mountain Lion is the early 2008 so you should be fine. I am very sorry thaty you are having these problems. What are the differences between our computer that are having these freezes with Mountian Lion and the other people's computers that aren't having this issue???
i have no clue what the differences are.
in any other case i would have though it was a Hard Drive problem but i just got a new 1TB drive a couple of months back. I paid a lot of money for this mac 4 years ago (3500 euro without the upgrade i've done along the way) and i tend to keep it clean and fresh when i can so that these kind of things wouldnt happen.
But I never would have thought that a software upgrade would cause so much damage.
i will see tomorrow what the service over here has to say and post any new updates about the matter.
i hope for the best and fear the worst.
Well problem solved.
After contacting the Apple phone service here in Greece and having a long chat with the operator and we came to the conclusion that the installation of Mountain Lion pushed my Nvidia 8800 GT 512MB over the hill and rendered it useless.
Thank God i have great friends and we managed to find and borrow a ATI Radeon HD XT 2600 256MB to replace my old graphics card and now everything works fine again, it started up and booted into MT without a problem.
So the conclusion is that Mountain Lion seems to be burning out graphic cards
and because of that i now have to hunt down and buy a new card that fits my 2008 Mac Pro.
PLUS i will be unistalling MT for the time being and going back to good old stable Snow Leopard, where i know everything is safe.
Still a very disapointing experience, Apple should look into this hard. Mountain Lion is breaking hardware and that is not cool.
thanks again for all the help.
since ive started to be more cautious on having the Mail.app running, I haven't had a single freeze in a month or so. I make sure Mail.app is never running. Also I have started to use Firefox instead of Chrome.
Now, I did update to 10.8.2 as soon as it was released, but still do not open Mail and Chrome so I don't know if the update fixed it for me.
No Mail.app and no Chrome, that's what works for me
i don't use chrome: i use safari, and i just got the screen freeze (mouse pointer moves but clicks do nothing; after reboot, console shows "kernel: **** Debug info for *possible* hang in MAIN graphics engine ****" many times in the system log at the time of the screen freeze).
this is maybe the second time it's happened. i'm running mountain lion 10.8.2 on a 13" macbook air i5 (2012).
This have not been solved in 10.8.2. THIS HAS NOT BEEN SOLVED!
I'm so frustrated by this issue. Was listen to some music in Spotify and had Safari up and running and a bunch of others apps. Boom, the computer freeze and the music kept on playing and I could move the mouse but not anything else.
In the console I got the message Sep 30 13:29:47 aeromoon kernel: **** Debug info for *possible* hang in MAIN graphics engine ****
same as before on 10.8.1. What is this anyway? Is the graphic card failing on the macbook pros retina or what?
My retina MBP was doing this under Lion, about every two or three days. I took it to an Apple Store on August 17, and they kept it for five days (including a weekend) to run a hardware diagnostic on it. When I got it back, they said that they hadn't found anything wrong, said it was probably due to an issue with migrating from my old MB, and recommended a clean system install (which I didn't do). Oddly enough, it hasn't had a freeze since then. I upgraded directly to 10.8.2 about a week ago, and it hasn't returned.