need help overclocking hd5850

hi guys, i'm running hd5850's in crossfire and i cant seem to overclock past a certain point, there is a limit set by ccc and i also tried afterburner,

anyway around this?

also, i tried using ati tool but this message comes up when i run the program

the kernal mode driver does not seem to be running, and then it wont detect either card.

What kind of 5850s do you have? Reference or non reference cards?

i dont know what reference means,

but i have one HIS hd5850 and then another one, cant remember make but its got metal pipes on the side??