Heya thanks for reporting. Right, the actual range used for attacking is precise, for instance 1.8. The indicator was previously simply clamped and is now rounded. I think I forgot some place where it is still clamped ^^ It's already on my list and will be fixed in the next release!
Ok great. But how does 1.8 correspond to the diagonal tiles? I have the feeling that this works more like 1 in cases where the creep is moving tangential to the range. Just a feeling though.