My Viewsonic VX2268WM started acting up after I alt-tabbed out of Dishonored and red lines started appearing on the right side of my screen with any 100% black  color as well as some dark blue colors. It does this even with no DVI or VGA connections as well as at the post screen. I can hear a quiet-ish noise from the monitor too.
 
I tried unplugging the monitor, reconnecting the DL-DVI cable, and trying the other DVI connection on my card. My secondary VGA monitor runs fine (older than this one). I tried connecting it to a laptop through VGA and the problem seemed to dissapear. Also, the problem occasionally disappears for a couple of minutes after bootup while still on DVI.
 
Here's a picture.

 

Hey OP, did you ever figure out what the problem was? The same thing happened to me earlier, but went away after I restarted. But I'm sure the problem is still there.