MacBook Air and iPhone have serious WiFi connection issues when using Airprint. Both seem to work fine surfing the internet and getting email, but when you need to print, the printer just doesn't seem to be there. The MacBook Air can see the printer, but nothing ever comes out. It just sits and spins and spins. Some solutions that people try is to restart the printer. I have connected regular PCs to the wireless printer as well and they seem to work fine (but they aren't using Airprint). But the problem isn't with the printer or the network. MacBook Air, iPad and iPhone all have issues staying connected to Airprint printers.
The problem is easy enough to solve with a work around, though it is annoying. Simply click on the WiFi connection on the top system bar and turn off the WiFi service, then turn it back on and that's it. Annoying, but it works.