I am having a problem trying to download apps through itunes on my mac, iphone and ipadvia wifi. The downloads are extremely slow. I have an airport extreme, but download speeds for everything else via wifi is just as fast as before. Not sure why just itunes is extremely slow, taking hours to download apps. I have rebooted my mac, rebooted my router, logged in an out of itunes, but still very slow. However, if I use 3G, it downloads.