I have a 2006 mac pro, and in March 2009 I bought an internal Airport Extreme Card. First few days it worked just fine however ever since its been giving me a full 5 bars to dropping to the very single one and then no connection at all. Sometimes it will even incrementally lose its signal, dropping from 5 to 4 to 3 bars and then back down to 1 in only a matter of minutes. I'm fed up with this. My macbook has 5 bars consistently from rooms further away from the router, its NEVER dropped its signal. My cheap Acer Aspire One with a Wireless G connection even has a better connection, its weaker but it never drops. I'm using a D-Link DIR-615 Wireless N router, and its been updated with the latest firmware. Its definitely not a router issue, its the card thats crapping out, seeing how two other devices connect to it just fine, from distances further away. Even when all three are put side by side; my mac, my macbook and my acer aspire one, the mac pro and the airport extreme does NOT work while the other two are getting nice consistent connections. I've tried changing channels, switching from b, g, to n, mixed and all that, and nothing has fixed my mac pro to work, my main computer. I bought it at an authorized apple reseller store and had it installed there too. Installation alone cost as much as the card itself, which is a joke, because the money that i paid for it i could have just bought a wireless usb adapter and used that instead of this headache of a product. Is there any 'warranty' or anything on these cards? I want an exchange on a WORKING wifi card.