I recently purchased a iMAC and when I got it running I experienced some problems. I took the unit to the Apple Store here in Sacramento, CA and they determined that it indeed had hardware problems. Apple was very prompt in solving the problem, they simply replaced it. The new unit is about one week old now and a few days ago I began to experience intermittent AirPort function. The modem just drops out from time-to-time. The signal is full strength all the horizontal bars are showing. I spoke with Apple briefly today but did not have the time to devote to a full diagnostic series of tests. I had the Apple folks on the line when I brought up the system using the AirPort function and they went over the setup with me and said that I had it configured correctly. Just as I look up now it's off line again for no apparent reason. I hover the curser over the icon and give it a tap and it comes to life again. I have two laptops with WiFi onboard and they work perfectly with the Wireless Router. ??? Any remarks, suggestions or insight as to what may be occurring? 