Answer
This question was answered on November 20, 2001.
Much of the information contained herein may have changed since posting.
Thanks for your question. If you have a lot of devices installed on your computer it could be that your CPU is overheating. Because of the effort made having to handle all the devices that you have on your computer (especially if you have it working as the server for another computer using your network card). Sometimes it locks up to cool down a little bit. Check the fan and make sure it is working properly.
Check that the keyboard is properly installed or if the pins are not damaged. Something you could try is a different keyboard for a few days, if this works then replace the keyboard. The keyboard cable could also be damaged. Good luck