your problem has nothing to do with dual channel, dual channel doubles the bandwidth of your installed ram NOT the speed.
If your ram and mobo/FSB support 200Mhz speed then you ought to be able to get both sticks running at that.
You can change configuration options for yout RAM in your BIOS, to enter which you press the indicated key when you switch your computer on.
Check out your mobo manual for supported configurations.
Intel core I7 920
6GB OCZ platinum 1600
Samsung 1TB F1 Spinpoint
Samsung SM2443BW 24"