Motherboard not using / even locating all physical RAM installed?!

[framm]

Hi. Im not very experienced with overclocking / fiddling with hardware, so I'm looking for some help! Today I got my hydro 100 CPU cooler in today and wanted to pump up my i7-920 up a bit..
Everything seemed to work like a charm until I realised something.
My computer is only using 2 GB ram out of my 6 GB installed ram. First I thought it was a OS problem (Using windows 7 ultimate), but realised its not.
Both in windows and in my BIOS it looks like there's only 2 GB physical RAM installed, even though I have all 6 slots loaded and they're all somewhat equally warm when I've been running the computer for hours!

The two highlightet ones says (the OS is in danish):
installed physical memory: 2,00 GB
physical memory in total: 1,99 GB


I overclocked my i7-920 to 4gz and didn't really tweak or do anything to my RAM settings other than following the common voltage recommendations. I even tried to reset all of my BIOS settings and remove my overclocking tweaks in order to see if it'd help. But it didnt.


Here are my voltage settings as well:

RAM info picture below - All the ram slots from 1 to 5 are identical. The 6th RAM slot is blank?? Dont know why.


Took a picture of my motherboard setup with all the ram plugged in. Link here:
http://img97.imageshack.us/img97/1360/thesetup.jpg
And a closeup picture of a single block of RAM. All the ram im using is the same type bythe way:
http://img708.imageshack.us/img708/8194/ramcloseup.jpg

Would be super awesome if anyone can help! I tried to recompile my computer from scratch but no luck again

[ApPy10]

Did you make sure that the ram that are seated on the motherboard are properly locked or so, of not then do the same and then check whether the system recognizes all the ram or not. I assume you have installed Windows 7 64 bit OS, because if it is 32 bit then it wont recognize more than 4 gb ram or so, as what i know.