i've been recently having lots of interference with my airport express in streaming airtunes. my computer is only like 1 metre away from it. it says in the help guide to go to admin utitliy > configure > to change the channels. yet i cant find this option in the menu. all there is to choose is security options, wireless options. and i have activated internet robustness i am joining my existing wireless. so that i can use my router for internet and airport just for airtunes. is there something wrong with my airport express?