Did you OC the card? To me it looks like the errors I get in some games when I run over clocked. If you have, take it down to stock and see if it persists.

Since you signed up for the game at this stage, I'm amazed that you even complain about this. You WILL experience many more of these.

I second this. I experience the exact same issue. DayZ hogs all bandwidth.

Edit: I sit on a stable 35Mb cable connection and I have no issues with other applications/games like BF4.

Confirmed. It also happens when you are in prone position. The rounds hit an invisible ground hitbox. Workaround is to go to kneeling position but that exposes you.

Confirmed issue. The same issue happens with other hotkeys like jump. It seems it has problems deciding whether it should do the old DayZ jig, jump or simply just do nothing. Doesn't matter if you run or walk.