120hz monitor blurry

I have a viewsonic 3d lcd monitor, I hooked it up to my newly built pc 2 weeks ago (dual link dvi) and the 120hz was working fine for about 4 days, now when I change the refresh rate to 100-120 hz the screen is very distorted and I can't even read anything on it -- but it looks clear and totally fine with 60 hz.. Do I need to buy a new dual link dvi cable? This could be a challenge because to my understanding you have to use the one that comes with the monitor, any help would be nice