I've noticed a slight bug in photoshop when editing pixels individually with the pencil tool on a grid. I use the normal brush tip which is the box with the crosshair in the center of it. So with the grid at 1x1 and zoomed in all the way can edit pixels easily. Except for the fact that when you click to place a pixel in doesn't place it at the point of the crosshair. I creates it at the bottom right corner of the box. This is so frustrating when you think it will be one place but it goes below and to the right. Here's an image to help the explanation.
And if you try the precise cursor it is even worse because it creates it in the same place but you can see the box. Does anybody know about a solution to this because creating pixel art with it is horribly difficult.