1600Hz memory is seldom recognised automatically as such, usually it is recognised as 1333 but it depends on how it has been programmed. Because 1600Hz is seen as not the norm, memory defaults to lower speeds to ensure you can boot up your system.
To get 1600Hz you will need to do this manually in the BIOS.
In the Visual BIOS go to the performance section, then Memory. Hopefully it should just be the case of moving the slider until you see the memory read 1600MHz, press F10 to save the changes and reboot.
Note that if you are using Intel's desktop utilities, it may still show the memory at 1067MHz because it doesn't report the actual memory speed, only the default one.
To double check the speed, go here CPUID - System & hardware benchmark, monitoring, reporting and download CPU-Z and under the memory tab the DRAM frequency x 2 gives you your running MHz.