Memory issue with X58 mobo

[Hodsocks]

I built a new pc with a i7 920 processor, an ASUS P6T deluve v2 mobo with 12GB of Corsair memory (6x2GB) and am having intermittent issues with the memory. The problem being that sometimes when I turn on the machine it will only recognise 8GB of memory, if I turn off the machine and reseat the memory it detects it all for a while and then it will lose the 4GB again.
It aslso won't run the Windows Experience index but reboots the machine part way through the test, I suspect this may also be memory related.
I will shortly update the BIOS to see if it resolves the issue but was wondering if you guys have any experience of this?

 

[Ritwik7]

Try running memtest86+ on each memory module to identify if there are any problems with the RAM sticks. I've heard that some motherboards often become unstable having all memory slots populated. Just a supposition. Actually such a thing should not happen.

Also go into BIOS and set the RAM timings and voltage to those specified by Corsair for your modules.