Either I'm too stupid to understand how the "Canvas Size..." dialog in Photoshop works, or something's seriously wrong. Usually, I want a 1 pixel border first and after that a bigger one with the opposite color (e.g. white, then black). The big border is never a problem, but the small one works only sometimes: often, the border is created just at two sides (usually on the right and at the bottom). What am I doing wrong? Anchor is set to the middle, and it doesn't matter if I work with relative or absolute values.