x11mod hangs on my 7950 once it starts to mine. -k darkcoin works

C:\sph-sgminer_x11mod\sgminer.exe -k x11mod -o stratum+tcp://east1.us.stratum.dedicatedpool.com:8006 -u medvezhonok.mgpu0 -p x -I 13 -g 2 -w 256 --lookup-gap 2 --gpu-engine 950 --gpu-memclock 1250 --gpu-powertune 20 --thread-concurrency 24000 --temp-cutoff 95 --temp-overheat 85 --temp-target 75 --api-listen --api-allow W:127.0.0.1