Random BSOD, Tried everything even new Motherboard and Memtest+

Right where to start...

I have built a custom PC, needless to say its not my first so I knew what I was doing.
I installed Windows 7 64 Ultimate to it and had it up and running fine, it ran for hours then blue screened on me, I thought it might have been a one off so tried again and it kept blue screening randomly.. no warning signs and not after a set time or a start up of a program, just randomly.

Decided to run Memtest on all 4x 4Gig sticks of corsair vengeance. They all passed twice. Took a hour for each stick to pass twice.
That made me think it wasn't the memory seeing as they were brand new and then tested with memtest.

I then tried to test the computer with only one stick in memory slot 1... still crashed.. memory slot two... still crashed and 3 and 4 still blue screening on all ports.

I tried reinstalling windows and drivers for everything about 6 times. Same issue continued.
Even removed Graphics card and ran without encase it was that causing a issue, and still same thing happened.

Brought another motherboard with same cu/memory slots etc to replace the current mobo so that I could rule out the mobo being the problem. even with new mobo fitted it still crashes.

Only other things it could be in my head is the CPU/PSU or HDD???

I have a mem dump but its about 700meg and is only of one BSOD from fresh install with new mobo no gfx card and basic setup no extras installed other than drivers..

Read this... Crash Reports - Read
Followed instructions and got some info.

On Mon 01/04/2013 00:36:18 GMT your computer crashed
crash dump file: C:\Windows\memory.dmp
This was probably caused by the following module: Unknown (0x6C682D9D)
Bugcheck code: 0x1A (0x41790, 0xFFFFFA800026A600, 0xFFFF, 0x0)
Error: MEMORY_MANAGEMENT
Bug check description: This indicates that a severe memory management error occurred.
This might be a case of memory corruption. More often memory corruption happens because of software errors in buggy drivers, not because of faulty RAM modules.
A third party driver was identified as the probable root cause of this system error.
Google query: MEMORY_MANAGEMENT

Not really sure what else I could post to help figure out whats wrong.

Tried updating the BIOS to new version.
Set to defaults.. crash, set to custom settings while talking it through with a PC tech guy and still same issue.. we both stumped and this has been going on for about a year now...

some one help?

I'll post any info that's needed, seriously want this fixed so I can code again without fear of BSOD.

Edit: as instructed here: Blue Screen of Death (BSOD) Posting Instructions
Attachment 262112