Why i have 20% rejects of my cards in this pool(with darkcoin settings) http://hash.altmine.net/static/ This is my setting "sgminer.exe --kernel darkcoin     -o stratum+tcp://hash.altmine.net:6356  -u fdg -p x --shaders 1792  --thread-concurrency 8192,21568 --lookup-gap 2,2 --worksize 256,256 --intensity 13,19  --gpu-powertune 20,20 -g 2,1 --temp-overheat  80 --temp-target 75 --temp-cutoff 90 --gpu-memclock 1500,1500 --gpu-engine 1100,1150"
http://s10.postimg.org/q6jslp4n9/sfsd.jpg