Good afternoon.
For the test, took the old Xeon E5450 and the latest version of Xmrig v2.5.3 (64 bit). When mining, it generates the "low difficulty share" error.
http://ifotohost.com/pic/402/gma3lb.jpgSo this is not the right algo, maybe you choose cryptonight lite witch is the not asic proof algorithm...
cryptonight lite variant 1 is also called cryptonight_v7 or CryptoNight-Lite AEON in xmrig, CryptoNight IPBC.
but I don't know if xmrig auto switch at block version 7 because for us, this is block version 4.
Also looks like this fork is ahead :
https://github.com/Bendr0id/xmrigCC and looks like this one auto detect the variant.
But I do not have the time to test all miners, that's why I provide the test pool. Maybe community can help there.