Why does my Mac disable my USB gaming keyboard?

Hi, I have a gaming keyboard I bought when I went to South Korea. It is a GTune MKF30 Keyboard, and it is from HANSUNG. the problem is that when I restart my Macbook Pro, it works perfectly. When I type in my password to log in, it works too. But as soon as I log into my mac, it shuts down. It has a colored backlight, and it is on before I log in, but when I log in, it shuts down as well. Help!