Look at the "Memory clock mode" and make sure it's half of what your RAM frequency is rated for in the specifications. 400 for 800MHz RAM, 533 for 1066MHz RAM, etc. If it isn't what it should be, change it manually.
Go in the "DRAM timing mode" and set it to manual. Manually change the timings in there to the ones you want.
TCL to 4CLK
TRCD to 4CLK
TRP to 4CLK
TRAS to 12CLK
Save and exit.
Check with thishttp://www.cpuid.com/softwares/cpu-z.html
LE If anything goes wrong, power off, take out the BIOS battery on the mobo for a while and put it back in. http://i.imgur.com/gGMqF.gif