So, as I stated, I have the 9C81.
Today, after my computer had been asleep through the night, I woke it up only to see that I had the vertical line problem. Not terrible, but enough that would bug me had I had to deal with it.
So, in an attempt to talk myself out of what I was seeing, I shut it down completely, took a shower, came back, and wham. All gone.
So, what's causing this problem? OSX getting confused about something? The screen gets confused?
Do we have any conclusive evidence of the problem yet?