Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Actually, my mac pro doesn't have an airport card. It's an early '08 and at least at that time, they didn't include one. It's seems crazy that they would leave something like that out, but they did.

It's not that Apple left the Airport card out of your Mac Pro, instead you neglected to order a Mac Pro with a Airport card in it. I have a early 2008 Mac Pro with an Airport card in it because I chose to order the Mac Pro with a Airport card in it.
 
i would try using g instead of n as sometimes the frequencies can be blocked by walls and other things and the higher the freq like 5ghz are closer together in there sin wave so a wall can actually hit and bounce it back
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.