Edit:
Are you sure Res.getEasyDifficultyTargetAsInteger()=115792089237316195423570985008687907853269984665640564039457584007908834672640 is correct?
I thought it would be 0xffff0000000000000000000000000000000000000000000000000000 for a difficulty-1-share, or 26959535291011309493156476344723991336010898738574164086137773096960 according to wolfram alpha.
I worked it out (thanks to luke-jr for the handholding).. I had the endianess around the wrong way when setting the easy target string and converting to a BigInteger. I've made a fix now and will create a new release shortly.