PS/2 Keyboard + iBook Problems

Hello there fine mac people. I bought a PS/2 to USB adapter so that I could use my old PS/2 keyboard with my iBook (needed a full-sized one, instead of the little one the 'book has). So I plug the keyboard into the adapter, then I plug the adapter into one of my iBook's USB ports, and...nothing happens. I've also tried rebooting with the keyboard plugged in. The LEDs light up, but it doesn't do anything when I type.

Is there something I have to install, a driver maybe...? I'm using Tiger, by the way.

Thanks.

same happens to me, help?