so, my parents finally moved a few weeks ago and they currently set up their iMacs using AirPort. Now, my mum's iMac is more or less as far away from the router as my dad's - but the signal seems much better, it just always works and pretty fast so. Now, when I check, my dad's signal seems always to be rather strong - but sometimes, the signal just interrupts and the iMac keeps looking for an Airport network around. Sometimes, you have to restart until it gets back to it again. Huh?