sleep & usb

I have an I-Mac running Panther 10.3.3. About 40% of the time when I wake it from sleep, the keyboard & mouse are frozen (mouse is pluged into keyboard). If I unplug the keyboard from the I-mac & plug it back in, it works fine - no longer frozen. Same thing with my I-sub subwoofer. When I unplug it & plug it back in, it works fine. I'm told that unplugging & plugging back in resets the usb. My usb printer seems to work no matter what.

Any ideas on how I can fix this?

Thanks