I don't know if you have tried this but have you timed and volted the ram correctly?
The reason I ask is because I have older Corsair dominator (DR2 800mhz) and unless I time and volt it correctly I get the same issues as you.
When I let my motherboard auto detect it it works somewhat OK. But, I get the odd BSOD here and there.
If I time it 4-4-4-12 @ 1.8v (what the board gives it by default) it is terribly unstable (sounds like yours). I have to force volt it to 2.1v which is what my memory was designed to do, at which point the voltage reading turns red in my bios because it thinks I am about to blow something up
But yeah, unless everything is set 100% to spec my computer is ridiculously unstable. I crash at post, I crash in bios. Madness.
Sorry if you have tried that. Tom seems to be right (sadly, not because he's right but because -) page faults usually turn out to be bad ram.
But make sure your timings are correct and present and that the voltage is also the right setting.
To find out if your ram is set up correctly simply load up CPUZ/CPUID whatever it's called now and click on the memory tab. Then make sure that the timings are what is stated either on the packet for the memory or down the sides of the memory. Make sure the voltage is what it should be also.
Also, there is another setting for DDR3, one I am not familiar with. But, recently a friend of mine who owns one of those wretched new Dell Alienwares (Dellienware !) put 6gb in his PC in place of his 3gb that came from the factory and he had your issues to a tee. Turned out there is a setting for bigger ram.. I forget what it was called now but when I see him I will ask.