Well try my bios settings at http://i4memory.com/f83/3x2gb-kingst...3-tests-18365/

for dual channel on Rampage extreme i had to loosen subtimings alot from default 4-7-4-7 to something like 9-11-9-11

READ to READ delay(S) : 9
READ to READ delay(D) : 11
WRITE to WRITE delay(S) : 9
WRITE to WRITE delay(D) : 11

my RMA has been approved by Kingston just need to contact local distributor to arrange replacement kit so will see how the replacements will fair