ATDD: Screen Flashing w/ Geforce Card! Help? (Windows 8)

[Ares]

I downloaded Amnesia about a year back, and it's always worked fine for me. I've beaten the game twice, no problems, played tons of custom stories, etc. Recently (early March), I downloaded the Windows 8 64 Bit Consumer Preview. Now, every time I try running the game, the screen flashes quickly, including the introduction cinematics (Frictional Games/Nordic game company logo). The screen just flashes between the game and blackness, making it extremely slow and unplayable. All of my drivers are up to date, including my graphics card. I just checked for the latest graphics card driver for my Nvidia Geforce GT 555m, but it's already installed on my computer. I tried re-installing it last week, but it didn't help. I just tried deleting my old settings.cfg like the troubleshooting guide said, as well as everything else it said, and I just updated the game. I've also tried running everything in-game at very low settings. All to no avail. I'm restarting my computer now, and maybe the problem will be solved. I'd like to not have to redownload the game.

Specs:
Lenovo Ideapad y570
Windows 8 Consumer Preview (64 bit)
Intel i5 2410m @ 2.3-2.9 GHZ
Nvidia Geforce GT 555m
4 GB RAM