My mom has an iMac G5 20 inch, 2.0ghz. She does not have wireless, just a cable modem hooked up. Yet, with her machine on, I picked up a signal from her computer with my laptop? I don't get it... is the iMac broadcasting an airport signal because its airport is on? It shows up in the airport preferences on my laptop as her computer broadcasting... very strange or I am just very dumb about this?