Some unusual memory issues

For some reason, when I read the memory speed in CPU-Z, two different frequencies are displayed for each module...

http://www.dansmom.com/upload/memory.JPG



Very unusual. I have 2x 1024mb PC6400 Corsair XMS2 ram modules. As I understand, since both of these modules are DDR800, both should be operating at 400mhz. Does anyone know how I can remedy this?

SYSTEM SETUP:
CPU: AMD Athlon 64X2 3800+
MOBO: M2N-SLI Deluxe
PSU: 430watt thermaltake
Graphics: Geforce FX5500 PCI
RAM: 2x 1024mb PC6400 Corsair XMS2

 

The shot on the left is what they are running at, the shot on the right is what they are capable of. You are showing two different sections of cpu-z. ed

 

Oh okay, cool.

I thought the shot on the right was showing what each individual module was running at
Thanks