Ya, I could see the artifacting when it happened quite clear, since the dots are white to red background.
Consider everything below 100 errors for a 10 min test, to be rock solid. Pretty much done every test I can do, and all is good.
As for AB, there is a v1.6.0 Final version out, head over:
herel.
Besides the obvious; where you need to go to "settings -> tick "unlock voltage control"". Also I recommend you to flash your card with a modified bios with "max volt" for the core aka v1.213. For most card there is a 70.00.21.00.xx bios out; "xx" is different depending if you have EVGA or another brand of the card.
At least this is how I did it :)