I'm able to pull 50 megabits/second on my iMac (over wifi) but I only get about 5 mbits/sec on my iPad and iPhone. Sometimes I've seen it close to 10 - but nowhere near as high as it should be. iPad w/3G, iPhone 4, Airport Extreme Early 2008. My Airport is up to date and I've tried switching channels, etc, but nothing. Any tips or ideas?