Comment 3 for bug 672232

The problem seems to be when you hold down the mouse button to continue painting. It works as expected on single clicks.

1. 32 x 32 canvas
2. Zoom 3600%
3. Turn on pixel grid
4. Choose pencil tool
5. Click on a box; while the mouse button is still down, move to the next box on the right (it paints to the top of the first box)