Mac OS X 10.6: Turning infrared (IR) reception on or off
You can turn infrared (IR) reception on or off using Security preferences. When you turn on IR reception for your computer, any IR device close to your computer can control it. You can turn IR reception off to prevent unwanted control of your computer or to prevent pairing with a IR remote control.
To turn IR on or off:
Choose Apple menu > System Preferences, click Security, and then click General.
Select “Disable remote control infrared receiver” to turn off IR reception, or deselect it to turn on IR reception.
To configure your computer to respond to the commands of a specific remote control, click Pair, and then follow the instructions displayed.