Ram not being recognized on motherboard

[fuzmaster]

I basically have a ram problem. I have 6 gigs of ram (2 gigs on each stick) on my motherboard (P7P55D EVO) that are secure and not loose or anything. Whenever I look under properties in windows 7 (64 bit), it only shows that it has 4 gigs. I checked out the rest of the sticks on my other computer and the sticks worked fine and the computer showed I added ram to it. I also recently just build a hackintosh (os x 10.6), and the ram isn't still recognized Why is this happening how can I fix it.

 

[davcon]

System configuration utility-->Boot/Advanced options-->uncheck maximum memory
I also have to ask is this dual channel DDR3 ram?

 

[fuzmaster]

yeah, they are dual channel