Just installed OSX ML as per guide (GA-H77N-WIFI) - but can't get gfx working

Just installed OSX ML as per guide (GA-H77N-WIFI) - but no boot!

Hi everyone!
I'm just setting up a ML install on a computer based on the Buyers Guide August.

I'm using a Gigabyte GA-H77N-WIFI as motherboard, with Intel Core i3 3225.
I followed this guide to the letter. In fact, the install went just fine, without a problem, didn't have to use any special options either.

Then, I used Multibeast, put the DSDT-GA-H77N-WIFI-F2.aml file on Desktop and added the Realtek 892 audio driver, and installation was successful, but I can't boot yet, since it shows me this error.

When I use the USB to boot, there's a huge gfx error. You can still clearly see the circle of the user picture though, so at least now it boots to user selection screen. But the computer is unusable.

Anyone know what I did wrong? I can't seem to figure it out. Already tried a clean wipe and reinstall, with same results.

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edit: ok, so I figured out that by putting my computer in suspend and then waking it restores the graphics to normal. So then I have a usable 1080p display, and the ability to run Multibeast again. But... I still can't get it to boot.

I also flashed my motherboard's bios to the latest version, but that didn't seem to affect things.
Also, I checked my installer.log after the Multibeast install and there was no mention of my DSDT file so I'm thinking I'm somehow doing this wrong—it's named DSDT.aml on the user desktop, isn't that how it's supposed to be done?

Sorry for bumping, but... is there really no one who has this same motherboard who could help me? It was the Buyers Guide August hardware, even. Someone should have this...

Newb here...I'm not sure this is your problem but I succeeded with his board using no DSDT file at all. I don't believe one is required for our board.