Wrong card. AirPort and BT are separate on the PowerMacs, not a single board.
on the core 2's, they're on the same card with something called a "run way" card.
I didn't think it would matter.It says nothing about PowerMacs in its description
YES.
What does System Profiler say under Network > Airport?
when I click on the little Airport icon, it doesn't even try (spinning wheel) to find a network.
My G5 doesn't take that antenna, it's the one with the strip on the back.