ASRock Z77 Extreme4 RAM Problem

So I am having a problem with my motherboard recognizing all my ram.

My motherboard is this : http://www.newegg.com/Product/Product.aspx?Item=N82E168...

My memory is this : http://www.newegg.com/Product/Product.aspx?Item=N82E168...

My CPU is this: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

So apparently at any given time only 2 memory slots are recognized. If I go into my BIOS, and I look at recognized memory, only two slots are shown, but if I go into a feature in BIOS where it maps out the whole motherboard and shows everything that is plugged, it indeed shows that my RAM is plugged in... <- if that made sense. The memory is not faulty as individually they all work. Also it seems like all the slots work as well, just not when there is 2 memory sticks already plugged in.

I have 64-bit Windows 7 Ultimate btw.

Also just installed CPU-Z and checked the "SPD" and all for slots show the same information :X Also CPU-Z in the
"Memory" tab shows that all 16GB are recognized but when I got to my Computer it says 8 gigabytes. :X

Any help would be greatly appreciated. Thanks!