If you have a problem with your Apple Remote not working after upgrading to OS 10.6 ‘Snow Leopard’, you aren’t alone. Unfortunately the problem is quite common, has numerous time-consuming suggested fixes that generally don’t work, and utterly predictable. Apple added a new facility to Snow Leopard that let you pair a specifc remote to a Mac, so people couldn’t mess about having ‘Remote Wars’. Because of this you might find your Mac refuses to see your remote simply because it thinks it’s paired to another one.
It took me all of about 15mins to work out how to fix it for a client, when another nearby Apple Reseller had apparently suggested they had to buy some 3rd party software to fix it. Odd world.