Ah, so it is not alignment issue, but rather because of cell size I see... If that's the issue I'll consider it for the next updates.
My suggestion for animated sprites is by not relying them to the certain tilesets size, but by height-weight division (row x height = 3 x 4), therefore you don't have to rely on fixed tilesizes (e.g must be multiplication of 16, 24, or 32, etc) when you get your assets from different people with different standards.