Cannot connect to a 5GHz Belkin router running OS X 10.8.3

Hey, I cannot connect to my Belkin router on the 5GHz frequency. I have checked whether my brand new MacBook Pro Retina supported the channel at which my router is broadcasting and it was in the list. I also tried to alter the SSID but it still doesn't show up in the list. I can connect to the 2.4GHz frequency but since there are many other routers near my house, the connection suffers because of the amount of signals around me. Some more information:

I'm running OS X 10.8.3

No updates are available, both for my router and mac

Any help would be much appreciated.