I have an iMac5,1 2.16 GHz Intel Core 2 Du running OS X 10.5.8 and I have a problem with the AirPort losing the signal from time to time. I have a BT broadband wireless router downstairs - I don't seem to have the same problem with my PC laptop's wifi.

There's no error message just every day or so it loses the signal which comes back in 5 - 15 minutes. Has anyone else had this?

Is it possible to purchase the AirPort as a part and change it?