Mining 2 x 5850s with 4gb ram only getting 260kh/s anyone doing better than that

"intensity" : "12",
"vectors" : "1",
"worksize" : "256",
"lookup-gap" : "2",
"thread-concurrency" : "4096",
"shaders" : "1440",
"auto-fan" : true,
"auto-gpu" : true,
"gpu-engine" : "765-896",
"gpu-fan" : "50-100",
"gpu-memclock" : "1200",
"gpu-memdiff" : "0",
"gpu-powertune" : "0",
"gpu-vddc" : "1.050",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"temp-cutoff" : "90",