Nice job, from 2,3 MH/s to 2,5 MH/s at my R9 280x GPUs

Continue improvements buddy

Change your command line from --kernel jackpotcoin to
--kernel jpc and get something between 3.5mh/s to 4.2mh/s instead

...and also get the 14.6 drivers like djm34 suggests as well!
Man, I'm not an idiot, I've changed the kernel. It's only
R9 280X not
290XI didn't misread, I know you have a 280x card. The speed range I quoted are roughly what you should be getting, even if you have not overclocked your card.
Here's 4 x 280x cards at I:20...
http://i59.tinypic.com/30xbsz8.gifYou should be getting at least 3.5mh/s with your lower intensity setting.
i have 2 R9280x
I updated to 14.6 drivers and changed to kernel to jpc then I changed my intensity to 20 and it went from 2.3mh to 3mh, here is how my miner is set up.
sgminer.exe --kernel jpc -o stratum+tcp://jpc.hashatme.com:3333 -u xxx -p xxx -d 0 -d 1 -I 20,20 --gpu-engine 1160,1160 --gpu-memclock 1800,1800 --thread-concurrency 11200,11200 -g 2 --auto-gpu --auto-fan --temp-target 70,70 --temp-overheat 80,80 --temp-cutoff 85,85
whats your config for your 280x?