aopen Wireless keyboard/mouse: keyboard not working

I have usb wireless keyboard/mouse and the keyboard doesnt work anymore
but i can still use the mouse. I know that it happen when i restart the
computer. It used to work when i change to another plug but i can do
that only once cause the keyboard doesnt work in that plug anymore
after it does that. And now none works i used em all. I'm writing with
my bros keyboard right now via my ps/2 plug.