Use the app that came with your Razer keyboard, Razer Synapse. If you don't have it download it here: http://www.razerzone.com/synapse/
Try updating the keyboard drivers, or try seeing if you accidentally set a delay timer.
I have bin using razer sins 2010 and this is the first time something like this happened (have used synapse sins then) and the only options available is brightness and gaming mode off and on.