Memory Memory seems ok individually but won't work together

Hi and thanks for any help in advance.
Recently I've had a few BSODs so I ran the windows memory diagnostic and it said there was a problem.
I have 2x2GB DDR2 Corsair sticks at 800Mhz, these have been working well as far as I know in this PC for 2 years.
I tried the just the first stick in the first slot and ran the test again, no problems.
So I tried just the Second stick in the first slot, no problems.
Seemed to indicate both sticks are okay.
Tried the second stick in just the the second slot, no problems. So both slots seem okay?
I tried both in as I had them again, finds problems...

So what exactly is the fault with?

Its the PC in my sig, currently not overclocked.

 

Is the voltage set correctly for the RAM?

 

Its set to auto on the motherboard, which is 1.84V. Looking online it seems like the RAM should be at 1.8V so I'll set it to 1.8V and run another test.

 

there's no way of setting it less than 1.84V as far as I can see, and its been like this before and worked then.
What else could it be?

 

Aren't the Corsair XMS2 stick 2.0 or 2.1v? Can you post the exact model number of the RAM?

 

CM2X2048-6400C5
Good job I just read that off it as they say 1.90V ver3.1 on them!
Will try 1.9 and run another test. Thanks

 

Set to 8.88V (it was that or 9.4) and ran the test, found no errors =).
Thanks both of you, once again the Bit-tech forums show their awesomeness.

 

Good job, glad it's sorted.

 

WOAH guessing you mean 1.88V otherwise we be cooking some chips tonight