Why is my memory in single channel mode?

[almoststew1990]

I have 2x 2GB of... well, this.

http://www.overclockers.co.uk/showproduct.php?prodid=MY-203-CS&groupid=701&catid=8&subcat=1517

I checked CPUz today because GTA IV is suddenly unplayable for some reason. uder 5fps. I have recently taken the RAM out and reseated it (Was troubleshooting another computer). It says 4GB but single channel. Also, Task Manager is only reporting 2GB. DRAM is 706MHz. It should end up at slightly under 1600 as I have overclocked my CPU so I lowered my DDR speed preset.

So what's going on here?

got 4 slots, both are in the blue slots.

 

[wazza300]

Test with only one stick in a blue slot,test both slots one at a time to make sure they are working,if it doesn't boot into windows with one stick in either of the blue slots then the ram itself or ram slot is faulty

 

[8 Pack]

Run Memtest on each stick individually also to make sure they are running to spec without error.