Strange movement with pixel art

[Justin C.]

     So I'm creating a game with 12x12 sprites and a zoom of 240x135. I'm getting this strange problem when moving diagonally. What happens (when holding down and left) is the player seems to move one pixel to the left, then a frame or two later move down one pixel. I'm guessing this has to do with my player's movement. Here's a gif of what's happening, and my playstate and player classes.

[PlayState on Pastebin]
[Player on Pastebin]

[Justin C.]

For some odd reason, the movement got less rigid. I guess it isn't as big as a deal anymore.

[Jeru Sanders]

Try turning on AA in the camera.

FlxG.camera.antialiasing = true

Once upon a time that fixed this, I've just been doing it out of habit, I'm not sure what it's actual behaviour is anymore.