P5Q with 8GB of RAM - Voltage help

Hi guys,

I was wondering if someone could point me in the direction for system stability

My machine looks like this:

Asus P5Q Deluxe
Core 2 Quad Q6600 2.4GHz S775
EVGA GeForce GTX 295
4x2GB 240DIMM PC2-6400 Gold

I have recently upgraded, adding the GTX 295 and an extra 2x 2GB sticks of RAM. Prior to this upgrade i was fine however now i am seeing quite a few 'Exception code: 0xc0000005' AppCrashes in high-load games. The secondary use of my PC is music production, but my sequencer and plugins are all 32bit. I see perfectly stability in these programs and in Windows in general.

Seeing as the only application error i am seeing is 0xc0000005, i would like to investigate RAM voltage\timings and general voltage issues before i look at other things.

I have recetly upgraded from Vista 64bit to Windows 7 6bit and am seeing exactly the same issue, so i am fairly convinced there is a hardware issue (be it a fault, or misconfiguration).

Could this potentially be a voltage\timing issue? My timings are set to 5-5-5-18 with a DRAM voltage of 2.1, which look to be the spec for my RAM. I have left the NB voltage well alone. Any tips or pointers for diagnopsing this issue woiuld be greatly appreciated.