Hi guys

Just bought a brand new Sapphire Tri-X OC R9290X.  I see that everyone is getting at least 850+ hashrates however I'm currently only sitting at 470kH/s.  What on Earth am I doing wrong?  I've even changed the motherboard, CPU, RAM, HDD and PSU to see if that would make a difference and nothing.  I'm running Catalyst 14.1 beta (also tried 13.12).  Using cgminer 2.11.4, also tried other versions as well as sgminer with no luck.  The batch file I'm executing is:
cgminer.exe --scrypt -o stratum+tcp://hk2.wemineltc.com:3336 -u username.1 -p x -I 19 -g 1 -w 256 --thread-concurrency 32765

I've many different variations from many different forums?  I'm started to think I've got a dud card here.  Can somebody help me out please as I'm only new to mining.
My PC is running Asus h81m-e M/B, i5-4670 CPU, 8GB 1333 RAM, 850W PSU (high quality).

Any ideas guys?  I seem to be the only one with this card getting such low hashrates out of the box.  The most I ever saw it get to was 690kH/s but for some reason I haven't been able to replicate this number.