well in that case i guess i might as well mention that when working with SDL it's a common rule to keep it to powers of two (edit: ok nevermind carolcat's got it) for whatever reason (guessing it's for the reason you've just posted there), and although i didn't work very much into LOVE2D when i attempted using it, i would assume it's something similar. so yeah
and also, when it adds transparent pixels around the image as you said it does, does it add it as a border around the image or does it expand downwards and right as if the top left corner is some sort of anchor point?